问题 读图填空题

生态平衡是一种                                   稳定状态。生态平衡依赖于生态系统的             能力。

答案

生物的数量  所占的比例  自我调节

题目分析:生态系统中各种生物的数量和所占的比例总是维持在相对稳定的状态,这种现象就叫做生态平衡,也就是说当生态系统处于平衡状态时,系统内各组成成分之间保持一定的比例关系,能量、物质的输入与输出在较长时间内趋于相等,结构和功能处于相对稳定状态,在受到外来干扰时,能通过自我调节恢复到初始的稳定状态。

阅读理解

In a great many cities, hundreds of people ride bicycles to work every day. In New York City, some bike riders have even formed a group called Bike for a Better City. They declare that if more people rode bicycles to work, there would be fewer automobiles in the downtown part of the city and so less dirty air from car engines.

For several years this group has been trying to get the city government to help bicycle riders. For example. They want the city to draw special lanes for bicycles only on some of the main streets, because when bicycle riders must use the same lanes as cars, there are accidents. Bike for a Better City feels that if there were special lanes, more people would use bikes.

But no bicycle lanes have been drawn. Not everyone thinks it is a good idea-they say it will slow the traffic. Some store owners on the main streets don’t like the idea-they say that if there is less traffic, they will have less business.

The city government has not yet decided what to do. It wants to keep everyone happy. On weekends, Central Park-the largest place of open ground in New York-is closed to cars, and the roads may be used by bicycles only. But Bike for a Better City says that this is not enough and keeps fighting to get bicycle lanes downtown.

小题1:In New York, a group of bike riders ________.

A.are keeping practicing for health

B.have no cars of their own

C.are complaining there are not enough buses

D.are trying to settle the problem of air pollution小题2:The advantage of the special lanes is that ________.

A.they will make cars and buses run slowly

B.they will make it easier for bike riders to go to parks

C.they will make the city more beautiful

D.the lanes will prevent accidents小题3:The government has not decided whether special lanes should be drawn _______.

A.so that everyone is disappointed

B.because there are different opinions

C.because most people travel by train

D.because Bike for a Better City is not strong enough小题4:Cars are not permitted to enter Central Park on weekends _________.

A.so that Bike for a Better City is pleased

B.so that everyone is happy

C.and bicycle lanes are drawn

D.but Bike for a Better City is still not satisfied

单项选择题