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

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.
51.what does the phrase “take the place of ”mean?
A.代替 B.就坐 C.就职 D.取得
52.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
53．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
54.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
55.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