16 de junio de 2008

Ciencias: Capítulo 5: Clasificación de la Materia

Capítulo 5:

Clasificación de la Materia

Fase: muestra de materia con límites físicamente bien definidos.

Materia Heterogénea: una porción de materia a la que se le distinguen sus partes, a simple vista o con microscopio, es heterogénea y presenta más de una fase. Este tipo de materia no es uniforme. Ej: fresco de frutas, pintura, madera, sangre, granito, leche sin procesar.

Materia Homogénea: la materia es homogénea cuando es igual en todas sus partes (posee solo una fase). Si esta materia se fragmenta, todos los trozos tendrán las mismas propiedades. Ej: vino, azúcar, sal, bronce, acero, aire, etc. Es uniforme.

Los 2 tipos de materia anteriores se pueden clasificar en sustancias puras y mezclas:

Sustancias Puras: se caracteriza por presentar la misma composición en toda la muestra, tener propiedades definidas y sus componentes no se separan por medio físicos sencillos.

· Elemento: tiene sólo un tipo de átomo, no se puede descomponer en sustancias más simples.

· Compuesto: formado por 2 o más clases de átomos que están unidos químicamente, se pueden descomponer en 2 o más elementos con métodos químicos.

Mezclas: 2 o más sustancias asociadas físicamente, se pueden separar con métodos físicos sencillos, las mezclas pueden combinarse en cualquier proporción.

· Coloides o Dispersiones Coloidales: sus partículas son tan pequeñas que van de 1 a 100 nanómetros y se llaman micelas. Pasan a través de los filtros corrientes. Los coloides se encuentran en el límite entre la disolución y la mezcla grosera. No se sedimentan, pasan a través del papel filtro, se separa por medio de membranas pergamino y dispersan la luz. Los coloides son muchos de los productos de uso diario. Tienen 2 fases; la fase dispersa (la que está en menor cantidad) y la fase dispersante (la que se encuentra en mayor cantidad). Los coloides sen encuentran en 3 estados:

· Gaseoso: cuando la fase dispersa es gas y la dispersante es líquido (se llama espuma. Ej: cerveza, espuma de afeitar) o el dispersante puede ser sólido (llamada espuma sólida. Ej: piedra pómez)

· Líquido: cuando la fase dispersa es líquido y la dispersante gaseosa (llamada aerosol líquido. Ej: niebla) o dispersante líquido (llamada emulsión. Ej: mayonesa) o dispersante sólido (llamada gel. Ej: jalea)

· Sólido: cuando la fase dispersa es sólida y la dispersante gaseosa (llamada aerosol gaseoso. Ej: humo, smog) o el dispersante es líquido (llamada sol. Ej: azufre en agua, pinturas) o sólido de dispersante (llamada sol sólido. Ej: piedras preciosas coloreadas)

· Heterogéneas o Groseras: tienen 2 o más fases. Los compuestos que la componen permanecen separados y se pueden observar. Cada fase es una porción homogénea, sus componentes se pueden separar sin que sus propiedades varíen. Se sedimentan en reposo, se separan por filtración, se separan con membrana y dispersan la luz. También reciben el nombre de mezclas mecánicas. Si una de los componentes es agua y los otros son sólidos estos se sedimentan al fondo por la gravedad. Ej: gallo pinto, basura… El tamaño de sus partículas es mayor a 100 nanómetros.

· Homogéneas o Disoluciones: tienen sólo una fase. Es uniforme. Reciben el nombre de disoluciones verdaderas. Si algún sólido se mezcla con un líquido y parece que el sólido desaparece, es una disolución. No se sedimentan, pasan a través de papel filtro, pasan a través de una membrana y no dispersan la luz. Las cantidades mezcladas pueden variar y se pueden separar por medio físicos. Presenta un soluto que es el material que es diluido y un solvente que es el material en el que se disuelve el soluto. Ej: alcohol con agua, sirope… El tamaño de sus partículas va de 0.05 nm a 1 nm. Sus partículas están distribuidas al azar.

Las disoluciones pueden estar en estado:

· Sólido: llamadas aleaciones cuando están hechas de 2 o más sólidos. También están en las cuales el soluto es gas y el solvente sólido como el hidrógeno en paladio, en las que el soluto es líquido y el solvente sólido como el mercurio en plata (amalgama), además de la amalgama cuando se diluye líquido con algún sólido se obtiene gel. Ej: acero, bronce, latón.

· Líquido: las más abundantes e importantes. En general el solvente es agua aunque existen otros. El solvente siempre es líquido. Las hay cuando el soluto es gas (Ej: cloro en agua) o cuando el soluto es líquido (Ej: alcohol en agua) o el sólido de soluto (Ej: sal en agua).

· Gaseosas: siempre son homogéneas y el soluto y el solvente son gaseosos. Ej: aire.

Las disoluciones se clasifican como toda la materia en homogénea y heterogénea y pueden ser:

· Moleculares: azúcar disuelta en agua.

· Atómicas: carbono disuelto en hierro.

· Iónicas: sal disuelta en agua.

Propiedades de los Coloides

· Sedimentación: son estables y la gravedad es muy pequeña como para sedimentarlas.

· Efecto de Tyndall: las disoluciones verdaderas son claras y transparentes y los coloides son de aspecto turbio esto se ve también al examinarlos con microscopio pues las disoluciones son homogéneas y los coloides heterogéneos y sus partículas están suspendidas en el medio. El recorrido de un rayo de luz a través de un coloide, las micelas dispersarán la luz, esto es el efecto de Tyndall, el cual es producido por la refracción y reflexión de la luz, en esto las partículas se distinguen como puntos luminosos en un fondo oscuro.

· Movimiento browniano: al examinar con el microscopio las partículas coloidales muestran un movimiento incesante en una trayectoria irregular en zigzag. Esto se debe a los choques no compensados de las moléculas del medio de dispersión con las partículas. Es independiente de la naturaleza de la partículas y entre más pequeña la partícula más rápido es el efecto. Esto fue descubierto por Robert Brown cuando vio en el microscopio que los granos de polen en agua se movían sin cesar.

Nota: la electroforesis es la carga eléctrica de un coloide.

Nota²: suspensiones: tipo de coloide que está en el límite entre los coloides y las mezclas groseras en el cual la fase dispersa está formada por partes grandes, generalmente son sólidos y no se disuelven en la fase dispersa por esta razón cuando se dejan en reposo se separan y se ven las fases fácilmente.

Usos de los Coloides

· Alimentos: leche, mayonesa, sopas claras, jaleas…

· Medicina: antibióticos orales, jarabes para la tos, emulsiones…

· Limpieza y Aseo: jabones (emulsionan la mugres), detergentes y colorantes son electrolitos coloidales o sea que tienen asociación de iones. A diferencia de otros coloides éstos tienen fórmula definida.

· Industria: látex (una suspensión coloidal de partículas de caucho), tintes, curtido de cueros, pinturas…

· Problemas: humo, polvo son producidos por su actividad. Dan problemas de navegación, tránsito, salud y bienestar personal.

Coloides en los Seres Vivos

· Fluidos corporales

· Los soles, geles y emulsiones son esenciales para la vida

· Agricultura: tierra. La arcilla y los humos suspendidos en el suelo forman un sol y son ingredientes coloides importantes del suelo

· La piel, músculos y otros tejidos son geles

· Protoplasma

· Sangre

· Membrana celular

· Proteínas

· Células vegetales

diego estuvo aqui

diego estuvo aqui

Ingles: Practica 2 Trimestre

Passive to Active Transformations
Take the following sentences in the passive voice and put them into the active voice.
Principio del formulario
1.The instructions have been changed.
Someone _________­­­________________________ the instructions.
2.She will have to be taught.
Someone __________________________________ her.
3.This car was manufactured in Japan by Toyota.
Toyota ___________________________________ this car in Japan.
4.Why aren't the exercises being finished on time?
Why ___________________________________ the exercises on time?
5.Casual clothes must not be worn.
You ____________________________________ casual clothes.
6.$400,000 in profit has been reported this year.
The company ____________________________________ $400,000 in profit this year.
7.The test will be given at five o'clock this afternoon.
The school ________________________________ the test at five o'clock this afternoon.
8.Students are required to wear uniforms at all times.
The school ___________________________________ students to wear uniforms at all times.
9.We were told to wait here.
Someone ____________________________________ us to wait here.
10.Lunch was being served when we arrived.
They ______________________________________ lunch when we arrived.
11.Lectures are recorded and posted on the Internet.
They __________________________________lectures on the Internet.
12.Portuguese has always been spoken in this village.
People in this village _____________________________________ Portuguese.



Retrieved and adapted from the World Wide Web: www.esl.about.com
Submitted by Prof. Silvia Saborío Taylor







Passive to Active Transformations- ANSWER KEY
Take the following sentences in the passive voice and put them into the active voice.
Principio del formulario
1.The instructions have been changed.
Someone has changed the instructions.
2.She will have to be taught.
Someone will have to teach her.
3.This car was manufactured in Japan by Toyota.
Toyota manufactured this car in Japan.
4.Why aren't the exercises being finished on time?
Why isn’t anyone finishing the exercises on time?
5.Casual clothes must not be worn.
You must not wear casual clothes.
6.$400,000 in profit has been reported this year.
The company has reported $400,000 in profit this year.
7.The test will be given at five o'clock this afternoon.
The school will give the test at five o'clock this afternoon.
8.Students are required to wear uniforms at all times.
The school requires students to wear uniforms at all times.
9.We were told to wait here.
Someone told us to wait here.
10.Lunch was being served when we arrived.
They were serving lunch when we arrived.
11.Lectures are recorded and posted on the Internet.
They record and post lectures on the Internet.
12.Portuguese has always been spoken in this village.
People in this village have always spoken Portuguese.

Retrieved and adapted from the World Wide Web: www.esl.about.com
Submitted by Prof. Silvia Saborío Taylor


Active to Passive Transformations
Put the following sentences into the passive voice or form.
Principio del formulario
1.They make shoes in that factory.
Shoes ______________________in that factory.
2.People must not leave bicycles in the driveway.
Bicycles ______________________ in the driveway.
3.They built that skyscraper in 1934.
That skyscraper ______________________ in 1934.
4.The students will finish the course by July.
The course ______________________ by July.
5.They are repairing the streets this month.
The streets ______________________ this month.
6.They make these tools of plastic.
These tools ______________________of plastic.
7.They have finished the new product design.
The new product design______________________.
8.They were cooking dinner when I arrived.
Dinner ______________________when I arrived.
9.Smithers painted 'Red Sunset' in 1986.
'Red Sunset' ______________________in 1986 by Smithers.
10.Did the plan interest you?
______________________ in the plan?
11.You should take care when working on electrical equipment.
Care ______________________ when working on electrical equipment.
12.They are going to perform Beethoven's Fifth Symphony next weekend.
Beethoven's Fifth Symphony ______________________ next weekend.
13.Someone will speak Japanese at the meeting.
Japanese ______________________ at the meeting.
14.Karen is going to prepare the refreshments.
The refreshments ______________________ by Karen.
Retrieved and adapted from the World Wide Web: www.esl.about.com
Submitted by Prof. Silvia Saborío Taylor


Active to Passive Transformations
Put the following sentences into the passive voice or form.
1.They make shoes in that factory.
Shoes are made in that factory.
2.People must not leave bicycles in the driveway.
Bicycles must not be left in the driveway.
3.They built that skyscraper in 1934.
That skyscraper was bult in 1934.
4.The students will finish the course by July.
The course will be finished by July.
5.They are repairing the streets this month.
The streets are being repaired this month.
6.They make these tools of plastic.
These tools are made of plastic.
7.They have finished the new product design.
The new product design has been finished.
8.They were cooking dinner when I arrived.
Dinner was being cooked when I arrived.
9.Smithers painted 'Red Sunset' in 1986.
'Red Sunset' was painted in 1986 by Smithers.
10.Did the plan interest you?
Were you interested in the plan?
11.You should take care when working on electrical equipment.
Care should be taken when working on electrical equipment.
12.They are going to perform Beethoven's Fifth Symphony next weekend.
Beethoven's Fifth Symphony is going to be performed next weekend.
13.Someone will speak Japanese at the meeting.
Japanese will be spoken at the meeting.
14.Karen is going to prepare the refreshments.
The refreshments are going to be prepared by Karen.
Retrieved and adapted from the World Wide Web: www.esl.about.com
Submitted by Prof. Silvia Saborío Taylor



Rewrite the sentences using a passive form.

1. IFL bought Nessafe.
a)
Nessafe had been bought by IFL.
b)
Nessafe was bought by IFL.
c)
Nessafe is bought by IFL.

2. Fred asked Simon.
a)
Simon was asked by Fred.
b)
Simon had been asked by Fred
c)
Simon is asked by Fred.

3. Caroline paid for the meal.
a)
The meal is paid for by Caroline.
b)
The meal has been paid for by Caroline.
c)
The meal was paid for by Caroline

4. Harry will meet you at the airport.
a)
You will have been met by Harry at the airport.
b)
You will be met by Harry at the airport.
c)
You would be met by Harry at the airport.

5. Tom respects Lindsay's opinion.
a)
Lindsay's opinion would be respected by Tom.
b)
Lindsay's opinion was respected by Tom.
c)
Lindsay's opinion is respected by Tom.

6. Jane upset me by what she said.
a)
I would be upset by what Jane said.
b)
I was upset by what Jane said.
c)
I would have been upset by what Jane said.

7. I'm going to inform John later today.
a)
John would be informed by me later today.
b)
John was informed by me later today.
c)
John is going to be informed by me later today.

8. The police arrested 12 people.
a)
12 people were arrested by the police.
b)
12 people have been arrested by the police.
c)
12 people should be arrested by the police.

9. Shiela might come to see you tomorrow.
a)
You might be visited by Shiela tomorrow.
b)
You will might be visited by Shiela tomorrow.
c)
You would be visited by Shiela tomorrow.

10. Frank Sinatra sang My Way..
a)
My Way was sung by Frank Sinatra.
b)
My Way had been sung by Frank Sinatra.
c)
My Way would be sung by Frank Sinatra.




Retrieved and adapted from the World Wide Web: www.better-english.com
Submitted by Prof. Silvia Saborío Taylor


























ANSWER KEY: Rewrite the sentences using a passive form.

1. IFL bought Nessafe.
a)
Nessafe had been bought by IFL.
b)
Nessafe was bought by IFL.
c)
Nessafe is bought by IFL.

2. Fred asked Simon.
a)
Simon was asked by Fred.
b)
Simon had been asked by Fred
c)
Simon is asked by Fred.

3. Caroline paid for the meal.
a)
The meal is paid for by Caroline.
b)
The meal has been paid for by Caroline.
c)
The meal was paid for by Caroline

4. Harry will meet you at the airport.
a)
You will have been met by Harry at the airport.
b)
You will be met by Harry at the airport.
c)
You would be met by Harry at the airport.

5. Tom respects Lindsay's opinion.
a)
Lindsay's opinion would be respected by Tom.
b)
Lindsay's opinion was respected by Tom.
c)
Lindsay's opinion is respected by Tom.

6. Jane upset me by what she said.
a)
I would be upset by what Jane said.
b)
I was upset by what Jane said.
c)
I would have been upset by what Jane said.

7. I'm going to inform John later today.
a)
John would be informed by me later today.
b)
John was informed by me later today.
c)
John is going to be informed by me later today.


8. The police arrested 12 people.
a)
12 people were arrested by the police.
b)
12 people have been arrested by the police.
c)
12 people should be arrested by the police.

9. Shiela might come to see you tomorrow.
a)
You might be visited by Shiela tomorrow.
b)
You will might be visited by Shiela tomorrow.
c)
You would be visited by Shiela tomorrow.

10. Frank Sinatra sang My Way..
a)
My Way was sung by Frank Sinatra.
b)
My Way had been sung by Frank Sinatra.
c)
My Way would be sung by Frank Sinatra.




Retrieved and adapted from the World Wide Web: www.better-english.com
Submitted by Prof. Silvia Saborío Taylor









































Active or Passive Voice
Choose the correct answer
1.Top of Form
Everybody ___ by the terrible news yesterday.
A. shocked
B. was shocked

Bottom of Form
2.
Top of Form
Mr. Green ___ at the University since 1989.
A. has been teaching
B. has been taught

Bottom of Form
3.
Top of Form
Not much ___ about the accident since that time.
A. has said
B. has been said

Bottom of Form
4.
Top of Form
A new book ___ by that company next year.
A. will publish
B. will be published

Bottom of Form
5.
Top of Form
He ___ the girl's name now.
A. remembers
B. is remembered

Bottom of Form
6.
Top of Form
The secretary ___ to her new boss yesterday.
A. introduced
B. was introduced

Bottom of Form
7.
Top of Form
Our plan ___ by the members of the committee.
A. is being considered
B. is considered

Bottom of Form
8.
Top of Form
He ___ responsible for the accident.
A. was holding
B. was held

Bottom of Form
9.
Top of Form
A prize ___ to whoever solves this equation.
A. will be giving
B. will be given

Bottom of Form
10.
Top of Form
When the manager arrived, the problem ___ .
A. was analyzing
B. was being analyzed







Retrieved and adapted from the World Wide Web: www.esl.about.com
Submitted by Prof. Silvia Saborío Taylor
Bottom of Form





















































ANSWER KEY
Active or Passive Voice
Choose the correct answer
1.Top of Form
Everybody ___ by the terrible news yesterday.
A. shocked
B. was shocked

Bottom of Form
2.
Top of Form
Mr. Green ___ at the University since 1989.
A. has been teaching
B. has been taught

Bottom of Form
3.
Top of Form
Not much ___ about the accident since that time.
A. has said
B. has been said

Bottom of Form
4.
Top of Form
A new book ___ by that company next year.
A. will publish
B. will be published

Bottom of Form
5.
Top of Form
He ___ the girl's name now.
A. remembers
B. is remembered

Bottom of Form
6.
Top of Form
The secretary ___ to her new boss yesterday.
A. introduced
B. was introduced

Bottom of Form
7.
Top of Form
Our plan ___ by the members of the committee.
A. is being considered
B. is considered


Bottom of Form
8.
Top of Form
He ___ responsible for the accident.
A. was holding
B. was held

Bottom of Form
9.
Top of Form
A prize ___ to whoever solves this equation.
A. will be giving
B. will be given

Bottom of Form
10.
Top of Form
When the manager arrived, the problem ___ .
A. was analyzing
B. was being analyzed







Retrieved and adapted from the World Wide Web: www.esl.about.com
Submitted by Prof. Silvia Saborío Taylor
Bottom of Form








































Passive voice 1
Re-write the sentences so that they have the same meaning as the original.
Principio del formulario
Final del formulario


Passive voice 2
Re-write the sentences so that they have the same meaning as the original.
Principio del formulario
Final del formulario



Retrieved and adapted from the World Wide Web: www.xtec.es.com

Submitted by Prof. Silvia Saborío Taylor







ANSWER KEY: Passive voice 1
Re-write the sentences so that they have the same meaning as the original.
Principio del formulario
Final del formulario


Passive voice 2
Re-write the sentences so that they have the same meaning as the original.
Principio del formulario
Final del formulario



Retrieved and adapted from the World Wide Web: www.xtec.es.com

Submitted by Prof. Silvia Saborío Taylor



























Verb Tenses
Simple Present / Present Continuous (Passive- Active)


Top of Form
Bottom of Form
Top of Form

1. Every Monday, Sally (drive) ________________ her kids to football practice.


2. Usually, I (work) ________________as a secretary at ABT, but this summer I (study) ________________French at a language school in Paris. That is why I am in Paris.


3. Shhhhh! Be quiet! John (sleep) ________________.


4. Don't forget to take your umbrella. It (rain) ________________.


5. I hate living in Seattle because it (rain, always) ________________.


6. I'm sorry, I can't hear what you (say) ________________because everybody (talk) ________________so loudly.


7. Justin (write, currently) ________________a book about his adventures in Tibet. I hope he can find a good publisher when he is finished.


8. A: Do you want to come over for dinner tonight?
B: Oh, I'm sorry, I can't. I (go) ________________to a movie tonight with some friends.


9. The business cards (print, normally ) ________________ by a company in New York. Their prices (be) ________________inexpensive, yet the quality of their work is quite good.


10. This delicious chocolate (make) ________________ by a small chocolatier in Zurich, Switzerland.



Retrieved and adapted from the World Wide Web: www.englishpage.com

Submitted by Prof. Silvia Saborío Taylor


Verb Tenses Answer Key
Simple Present / Present Continuous (Passive- Active)


Top of Form
Bottom of Form
Top of Form

1. Every Monday, Sally (drive) drives her kids to football practice.


2. Usually, I (work) work as a secretary at ABT, but this summer I (study) am studying French at a language school in Paris. That is why I am in Paris.


3. Shhhhh! Be quiet! John (sleep) is sleeping.


4. Don't forget to take your umbrella. It (rain) is raining.


5. I hate living in Seattle because it (rain, always) always rains.


6. I'm sorry, I can't hear what you (say) ‘are saying because everybody (talk) is talking so loudly.


7. Justin (write, currently) is currently writing a book about his adventures in Tibet. I hope he can find a good publisher when he is finished.


8. A: Do you want to come over for dinner tonight?
B: Oh, I'm sorry, I can't. I (go) ‘m going to a movie tonight with some friends.


9. The business cards (print, normally ) are normally printed by a company in New York. Their prices (be) are inexpensive, yet the quality of their work is quite good.


10. This delicious chocolate (make) are made by a small chocolatier in Zurich, Switzerland.



Retrieved and adapted from the World Wide Web: www.englishpage.com

Submitted by Prof. Silvia Saborío Taylor
Bottom of Form


Bottom of Form















The Passive Voice
A shark has eaten the Prime Minister
The Prime Minister has been eaten by a shark
Change the sentences from the active to the passive.

They grow coffee in Kenya.
1
______________________________________________________ .

They publish The Times newspaper in London.
2
______________________________________________________ .

They make shoes in Calatayud.
3
______________________________________________________ .

They transport oranges from Valencia to Germany in special crates.
4
______________________________________________________ .

They are sending the parcel by sea.
5
______________________________________________________ .

They are destroying the forests in Indonesia.
6
______________________________________________________ .

The shark ate the man.
7
______________________________________________________ .

The arsonist started the fire.
8
______________________________________________________ .

The police took him away.
9
______________________________________________________ .

They've treated him very well.
10
______________________________________________________ .

They haven't cleaned the kitchen yet.
11
______________________________________________________ .

They didn't punish him for what he did.
12
______________________________________________________ .
Retrieved from World Wide Web
Submitted by Prof. Silvia Saborío Taylor
ANSWER KEY: The Passive Voice
A shark has eaten the Prime Minister
The Prime Minister has been eaten by a shark
Change the sentences from the active to the passive.

They grow coffee in Kenya.
1
Coffe is grown in Kenya.

They publish The Times newspaper in London.
2
The Times newspaper is published in London.

They make shoes in Calatayud.
3
Shoes are made in Calatayud.

They transport oranges from Valencia to Germany in special crates.
4
Oranges are transported from Valencia to Germany in special crates.

They are sending the parcel by sea.
5
The parcel is being sent by sea.

They are destroying the forests in Indonesia.
6
The forests are being destroyed in Indonesia.

The shark ate the man.
7
The man was eaten by the shark.

The arsonist started the fire.
8
The FIRE was started by the arsonist.

The police took him away.
9
He was taken away by the police.

They've treated him very well.
10
He has been treated very well.

They haven't cleaned the kitchen yet.
11
The kitchen hasn’t been cleaned yet.

They didn't punish him for what he did.
12
He wasn’t punished for what he did.
Retrieved from World Wide Web
Submitted by Prof. Silvia Saborío Taylor






Verbs in Context: Active vs. Passive Voice.

1.Coca Cola _______________ in Atlanta in 1886. Today it _______________ in cans and bottles.
a)was being invented / was sold
b)invented / sells
c)was invented / is sold
d)invented / is sold


2.My friend Pierre _______________ his leg while he _______________ in the Alps.
a)broke / was skiing b) broke / skied
a)was breaking / skied d) was breaking / was skiing


3.The Old Man and the Sea is a novel. It _______________ by Hemingway. It’s about a fisherman called Santiago that _______________ a fish in 84 days.
a) wrote / hasn’t caught b) was wrote / didn’t caught
c) wrote / isn’t catching d) was written / hasn’t caught


4.Black Eyed Peas’ last concert was a complete fiasco. Fans who couldn’t get tickets _______________ stones at security guards.
a) have thrown b) threw
c) did throw c) were thrown


5.We _______________ each other since we were in primary school.
a) didn’t see b) don’t see
c) haven’t seen d) haven’t been seen


6.Children _______________ after by their guardians.
a) should be looked b) should being looked
c) should been looked d) should look


7.Sorry, but I have to leave now. My friends _______________ for me for almost one hour.
a) ‘ve been waiting b) waited
c) ‘ve been waited d) were waiting


8.This semester Alicia _______________ her project on Sidney’s history. She _______________ about two hours at the library everyday.
a) does / spends b) does / is spending
c) is done / is spending d) is doing / spends






Submitted by Prof. Silvia Saborío Taylor


9.A: Why _______________ a taxi to the airport last weekend?
B: Because they _______________ the bus.
a) they took / missed b) do they take / miss
c) did they take / missed d) have they taken /have missed


10.A: How long _______________ Kevin and Chuck?
B: Mmm, since our school days. We _______________ one day in basketball practice.
a) do you know / meet b) have you known / met
c) are you know / met d) have you been knowing / meet
11.The funniest character of The Simpsons is probably Homer. He _______________ as an incompetent, funny man. He loves eating doughnuts.
a) presents b) is presenting
c) is presented d) presented


12.Bar codes _______________ rows of black lines that contain information about products. Woodland & Silver _______________ the first code in the late 1950’s. Bar codes _______________ in supermarkets.
a)are being / created / are use b) are / create / used
a)were / created / used d) are / created / are used


13.A: What do you think of music magazines?
B: I never read them. In fact, I _______________ music magazines. I prefer listening to music.
A: Well, right now I _______________ a very exciting one. I could lend it to you.
a) don’t like / ‘m reading b) isn’t liked / ‘m being read
c) aren’t liking / ‘m reading d) don’t like / read


14.Many oceans and forests _______________ by Greenpeace since 1971.
a) have protected b) have been protecting
c) protected d) have been protected


15.The Great Wall of China _______________ about 2,000 years ago. The construction of the wall _______________ an army of local people, soldiers, and prisoners.
a) built / required b) was built / required
c) built / was required d) was build / was require







Submitted by Prof. Silvia Saborío Taylor








*ANSWER KEY

Verbs in Context: Active vs. Passive Voice.

16.Coca Cola _______________ in Atlanta in 1886. Today it _______________ in cans and bottles.
a)was being invented / was sold
b)invented / sells
c)was invented / is sold
d)invented / is sold


17.My friend Pierre _______________ his leg while he _______________ in the Alps.
a)broke / was skiing b) broke / skied
b)was breaking / skied d) was breaking / was skiing


18.The Old Man and the Sea is a novel. It _______________ by Hemingway. It’s about a fisherman called Santiago that _______________ a fish in 84 days.
a) wrote / hasn’t caught b) was wrote / didn’t caught
c) wrote / isn’t catching d) was written / hasn’t caught


19.Black Eyed Peas’ last concert was a complete fiasco. Fans who couldn’t get tickets _______________ stones at security guards.
a) have thrown b) threw
c) did throw c) were thrown


20.We _______________ each other since we were in primary school.
a) didn’t see b) don’t see
c) haven’t seen d) haven’t been seen


21.Children _______________ after by their guardians.
a) should be looked b) should being looked
c) should been looked d) should look


22.Sorry, but I have to leave now. My friends _______________ for me for almost one hour.
a) ‘ve been waiting b) waited
c) ‘ve been waited d) were waiting


23.This semester Alicia _______________ her project on Sidney’s history. She _______________ about two hours at the library everyday.
a) does / spends b) does / is spending
c) is done / is spending d) is doing / spends






Submitted by Prof. Silvia Saborío Taylor


24.A: Why _______________ a taxi to the airport last weekend?
B: Because they _______________ the bus.
a) they took / missed b) do they take / miss
c) did they take / missed d) have they taken /have missed


25.A: How long _______________ Kevin and Chuck?
B: Mmm, since our school days. We _______________ one day in basketball practice.
a) do you know / meet b) have you known / met
c) are you know / met d) have you been knowing / meet

26.The funniest character of The Simpsons is probably Homer. He _______________ as an incompetent, funny man. He loves eating doughnuts.
a) presents b) is presenting
c) is presented d) presented


27.Bar codes _______________ rows of black lines that contain information about products. Woodland & Silver _______________ the first code in the late 1950’s. Bar codes _______________ in supermarkets.
a)are being / created / are use b) are / create / used
b)were / created / used d) are / created / are used


28.A: What do you think of music magazines?
B: I never read them. In fact, I _______________ music magazines. I prefer listening to music.
A: Well, right now I _______________ a very exciting one. I could lend it to you.
a) don’t like / ‘m reading b) isn’t liked / ‘m being read
c) aren’t liking / ‘m reading d) don’t like / read


29.Many oceans and forests _______________ by Greenpeace since 1971.
a) have protected b) have been protecting
c) protected d) have been protected


30.The Great Wall of China _______________ about 2,000 years ago. The construction of the wall _______________ an army of local people, soldiers, and prisoners.
a) built / required b) was built / required
c) built / was required d) was build / was require







Submitted by Prof. Silvia Saborío Taylor




























Passive Voice. Change the following sentences from active to passive, only if possible.
1. Children cannot open these bottles easily.
_________________________________________________________________________________
1. The government built a road right outside her front door.
_________________________________________________________________________________
3. Some children were visiting the old City Hall.
__________________________________________________________________________________
4. Corrosion has damaged some parts of the ship.
__________________________________________________________________________________
5. The robber was running directly to the metro station.
__________________________________________________________________________________
6. Did Nicholas Copernicus change the study of astronomy?
__________________________________________________________________________________
7. The party will celebrate his retirement.
__________________________________________________________________________________
8. The professors were discussing the oral exam right in front of Todd.
_________________________________________________________________________________
9. I have eaten at very good and cheap restaurants around the world.
__________________________________________________________________________________
10. The construction workers are making street reparations all month long.
_________________________________________________________________________________
11. My son eats all the homemade cookies.
_________________________________________________________________________________
12. Somebody discovered the vaccination against polio in 1952.
_________________________________________________________________________________
13. Does a writer write the script of a movie?
_________________________________________________________________________________
14. People speak Portuguese in Brazil.
_________________________________________________________________________________
15. The children are playing in the backyard.
_________________________________________________________________________________
16. Yandel is going to present a tremendous show at the MTV’s Video Music Awards.
_________________________________________________________________________________
Verbs in Context: Active vs. Passive. Read carefully and choose the correct form of the verb.

1. I still can't believe it! My bicycle _____ last night.
a. was stolen b. was stealing c. stolen d. stole

2. Something funny _____ in class yesterday.
a. happened b. was happened c. happens d. is happened

3. Today, many serious childhood diseases _____ by early immunization.
a. can prevent b. can be prevented

4. Many U.S. automobiles _____ in Detroit, Michigan.
a. manufacture b. are manufacturing
c. manufactures d. are manufactured

5. A: "When _____?"
B: "In 1928."
a. penicillin was discovered b. was penicillin discovered
c. did penicillin discover d. penicillin discovered

6. Normally, Vitamin C _____ by the human body. It gets into the blood stream quickly.
a. absorbs b. is being absorbed c. is absorbing d. is absorbed

7. A: "When can I have my car back?"
B: "I think it will _____ tomorrow night."
a. finish b. be finished c. have finished d. be finish

8. The Mayan Indians _____ a sophisticated calendar more than seven
centuries ago.
a. were developed b. are developed c. developed d. develop

1.Yesterday there was a chaos in Puddle Town when an elephant escaped from the local zoo. “ I _____ my car when an enormous elephant _____ in front of my car.”
a. was driving / walked b. drove / walked
c. was driving / was walking d. drove / was walking

10. Somebody _____ my car last week. Now I have to take the bus.
a. was stolen b. stoled c. stole d. stolen

11. I have to take the bus because my car _____ last week.
a. stole b. was stolen c. stolen d. stoled

12. Jane _____ ballet since she was five years old.
a. practice b. has been practicing c. practiced d. has been practiced

1.The first thermometer _____ in 1615.
a. invents b. is invented
c. was invented d. invented

14. I had a terrible day yesterday. First, my shirts _____ at the dry cleaner’s! Then, my favorite sweater _____ by my dog!
a. destroyed / ate b. were destroyed / was eaten
c. was destroyed / was eaten d. destroyed / was eaten

15. Sally can’t go home. Her house _____ now.
a. paints b. is painting c. is being painted d. is painted

16. A: _____ you ever _____ South America?
B: Sure! I _____ to Brazil and Chile last year.
a. Did / visit / went b. Do / visit / go
c, Have / been visited / go d. Have / visited / went