问题 选择题

如下图所示,原来置于黑暗环境中的绿色植物移到光下后,CO2的吸收量发生了改变。据图判断下列叙述中正确的是

[ ]

A.曲线AB段表示绿色植物没有进行光合作用

B.曲线BC段表示绿色植物仅进行光合作用

C.B点表示绿色植物光合作用和呼吸作用速率相等

D.整段曲线表明,随光照强度递增,光合作用增强,呼吸作用也增强

答案

答案:C

阅读理解

阅读短文,从题中所给的A, B, C, D四个选项中选出最佳答案。

       A kind of little cars may some day take the place of today's ones. If everyone drives such cars in the future,

there will be less pollution in the air. 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 (汽油).

       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 air 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 is ____ that of the future cars. [ ]

A. much smaller than

B. much the same as

C. three times as large as

D. a little larger than

3. Which of the following is not true? [ ]

A. Big cars cost more to own and to drive.

B. Big cars are not useful for long trips.

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

D. Small cars are slower 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

完形填空