阅读理解。

     Why did the chicken cross the road? To get to the other side.

     Most people know this joke. But recently, some people have been much more worried about how

the grizzly(灰白的) bear and mountain lion can cross the road.

   "Millions of animals die each year on U.S. roads," the Federal Highway Administration reports. In

fact , only about 80 ocelots(豹猫), an endangered wild cat, exist in the U. S. today. The main reason?

Road kill.

   "Eco-passages" may help animals cross the road without being hit by cars. They are paths both over

and under roads. "These eco-passages can be extremely useful, so that wildlife can avoid road accidents," said Jodi Hilty of the Wildlife Protection Society.

   But do animals actually use the eco-passages? The answer is yes. Paul Beier of Northern Arizona

University found foot marks left by mountain lions on an eco-passage that went under a highway. This

showed that the lions used the passage.

   Builders of eco-passages try to make them look like a natural part of an area by planting trees on and

around them. Animals seem to be catching on. Animals as different as salamanders(火蜥蜴)and

grizzly bears are using the bridges and underpasses(地下通道,下穿交叉道).

   The next time you visit a park or drive through an area with a lot of wildlife, look around. You might

see an animal overpass(越过,通过)!

1. The writer uses the example of "ocelots" to show that __________.

A. an increasing number of animals are killed in road accidents

B. the driving conditions have improved greatly

C. the measure for protecting wildlife fails to work

D. wild animals have become more dangerous

2. From the news story, we know an eco-passage is __________.

A. an underground path for cars            

B. a fence(栅栏) built for the safety of the area

C. a passage(通道) for animals to cross the road  

D. a bridge for animals to get over a river

3. The underlined(划线) part "animals seem to be catching on"  means __________.

A. animals begin to realize the dangers on the road

B. animals begin to learn to use eco-passages

C. animals are crossing the road in groups

D. animals are becoming safer

4. This passage is written to __________.

A. protect the endangered animals

B. call on drivers to be careful when seeing animals on roads

C. introduce a new way to help protect animals

D. tell us the main reason for the killing of animals in the US