A kind of little cars may some day take the place of today’s cars. If everyone drives such cars in the future，there will be less pollution in the car. There will also be more space for parking cars in cities，and the streets will be less crowded. Three such cars can fit in the space now needed for one car of the usual size.

The little cars will cost much less to own and to drive. Driving will be safer，too，as these little cars can go only 65 kilometers an hour. The cars of the future will be fine for getting around a city，but they will not be useful for long trips. Little cars will go 450 kilometers before needing to stop for more gasoline.

If big cars are still used along with the small ones，two sets of roads will be needed in the future. Some roads will be used for the big，fast cars and other roads will be needed for the slower，small ones.

1. There is much pollution in the car today because________.

A. people drive big cars

B.people drive little cars

C.the cars go 65 kilometers an hour

D.the cars can go 450 kilometers an hour

2.The usual size of cars today are________that of future cars.

A. much smaller than　　　　　　　　　　　　　　　　　　    B.much the same as

C.three times as large as　　　　　　　　　　　　　　　　    D.a little larger than

3.We can learn from the passage that________.

A. big cars cost less to own and to drive

B.big cars are not useful for long trips

C.the cars of the future will be much smaller than today’s cars

D.small cars are faster than big ones

4.The street will be less crowded because________.

A. there will be fewer cars in the future

B.there will be fewer passengers in the street

C.driving future cars will be safe

D.future cars will be much smaller

5.Two sets of roads may be needed in the future because________.

A. there will be too many cars in the future

B.more and more people will get around a city

C.big cars and little cars may be used along with each other

D.it looks more beautiful to have two sets of roads

 

A kind of little cars may some day take the place of today's cars. If everyone drives such cars in the future, there will be less pollution in the car. There will also be more space for parking cars in cities, and the streets will be less crowded. Three such cars can fit in the space now needed for one car of the usual size.

The little cars will cost much less to own and to drive. Driving will be safer, too, as these little cars can go only 65 kilometers an hour. The cars of the future will be fine for getting around a city, but they will not be useful for long trips. Little cars will go 450 kilometers before needing to stop for more gasoline.

If big cars are still used along with the small ones, two sets of roads will be needed in the future. Some roads will be used for the big, fast cars and other roads will be needed for the slower, small ones.

1. There is much pollution in the car today because________.(　)

A. people drive big cars

B. people drive little cars

C. the cars go 65 kilometers an hour

D. the cars can go 450 kilometers an hour

2. The usual size of cars today are ________ that of future cars.(　)

A. much smaller than

B. much the same as

C. three times as large as

D. a little larger than

3. We can learn from the passage that________.(　)

A. big cars cost less to own and to drive

B. big cars are not useful for long trips

C. the cars of the future will be much smaller than today's cars

D. small cars are faster than big ones

4. The street will be less crowded because________.(　)

A. there will be fewer cars in the future

B. there will be fewer passengers in the street

C. driving future cars will be safe

D. future cars will be much smaller

5. Two sets of roads may be needed in the future because________.(　)

A. there will be too many cars in the future

B. more and more people will get around a city

C. big cars and little cars may be used along with each other

D. it looks more beautiful to have two sets of roads

 

Light travels at a speed which is about a million times faster than the speed of sound. You can get some idea of this difference by watching the start of a race. If you stand some distance(距离) away from the starter, you can see smoke from his gun before the sound reaches your ears.

This great speed of light produces some strange facts. Sunlight(太阳光) takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light rays left the moon 1.3 seconds before they reached you. The nearest star is so far away that the light that you can see from it tonight started to travel towards you four years ago at a speed of nearly 2 million km. per minute. In some cases, the light from one of tonight’s stars had started on its journey to you before you were born.

Thus, if we want to be honest, we can’t say, “The stars are shining tonight.” We have to say instead, “The stars look pretty. They were shining four years ago, but their light has only just reached the earth.”

1.Light speed is ______ sound speed.

A. as fast as                          

B. a million times slower than

C. about millions of times faster than     

D. about a million times faster than

2. If you stand 200 meters away from a man who is firing a gun to start a race, you will find out that ______.

A. you can hear the sound before you see the smoke

B. the sound does not travel as fast as light

C. the sound will reach you before the man fires

D. sound travels about a million times faster than light

3.Sunlight obviously(显然的) ______ than the light of the moon.

A. has to travel a greater distance          

B. moves less quickly

C. travels much more quickly            

D. is less powerful

4. The scientific way of saying "The stars are shining tonight" should be ______.

A. the stars have been shining all the time

B. the stars seen tonight will shine four years later

C. the stars were shining long ago but seen tonight

D. the starlight seen today could be seen four years ago

 

Miss Evans taught physics in a London school. Last month she was explaining to her class about sound, and she decided to test them to see how successful she had been in her work. She said to them, Now, I have a sister in Washington. If I was calling her on the telephone, and at the same time you were 20 meters away and listened to me from the other side of the street, who could hear what I said earlier, my sister or you? And why?
The cleverest boy at once answered, “Your sister, Miss Evans, because electricity (电)travels faster than sound waves(波).” That's very good, Miss Evans answered, but then one of the girls put up her hand, and Miss Evans said, Yes, Betty?
“I don't think so. Betty said, Your sister would hear you earlier because when it's eleven o'clock here, it's only six o'clock in Washington.”
(   )6. Miss Evans was teaching her class __________.
A. about sound                       B. to hear some strange sound
C. about electricity                    D. how to say time
(   )7. She wanted to make her students know__________.
A. whether she could hear her sister in Washington
B. whether her students could hear her from 20 meters away
C. which was faster, London or Washington
D. electricity travels faster than sound waves
(   )8. The cleverest boy thought that___________.
A. sound waves travel faster than electricity
B. they would hear her sister in Washington first
C. Miss Evans's question wasn't right
D. Miss Evans's sister would hear her earlier
(   ) 9. Miss Evans________.
A. thought Betty's answer was much better
B. thought the cleverest boy's answer wasn't so good
C. was satisfied with what the girl had said
D. was satisfied with(对...感到满意) what the cleverest boy had said
(   )10. Betty thought the cleverest boy was wrong, because_____________.
A. clocks in Washington showed a different time from those in London
B. electricity was slower than sound waves
C. they were only 20 meters away from the telephone
D. electricity travels as fast as sound waves