题目内容：

One thing the tour books don't tell you about London is that 2,000 0f its residents (屠民) are foxes. They ran away from the city about centuries ago after developers and pollution moved in. But now that the environment is cleaner, the foxes have come home.

"The number and variety of wild animals in urban c城市的) areas is increasing," says Corner Jones. A survey of the wildlife in New York's Central Park last year counted 14 kinds of animals. A similar survey carried out in the 1890's counted only five kinds.

Several changes have brought wild animals to the cities. First, the air and water quality in many cities have improved as a result of the 1970s pollution-control efforts. Meanwhile, rural areas have been built up, and many animals have gone to the area outside the centre of a city. In addition, urban wildlife refuges (避难处) have been created. The Greater London Council last year spent  $ 750, 000 to buy land and build 10 permanent (永久性的) wildlife refuges in the city.  As a result, many birds are now living in the city. By 1970 the birds had died out east of the Mississippi because the DDT had made their eggs too thin to support life.

That year, scientist Tom Cade of Cornell University began raising the birds for release in cities, for cities afforded abundant food.

Cities can attract wild animals without turning them harmful. The key is to create habitats where they are able to live happily. Such habitats can even be useful. In San Francisco, the local government is testing different kinds of rainwater control basins to see not only which ones keep the cleanest water but which will attract the most birds.

1. What is the passage mainly about?

A. 2,000 foxes returning to London.

B. Wild animals living in zoos.

C. Wildlife returning to some larger cities.

D. The great enemy of wildlife.

2. It can be inferred from the passage that

A. Londoners are putting more and more wild animals into their zoos

B. Londoners are happy to see wild animals return to their city

C. Londoners are trying to move wild animals back to the countryside

D. Londoners have welcomed the wild birds, but found foxes a problem

3.According to the passage, the number of species of wildlife in New York's park            .

A. is slowly going down

B. is the same as that in other cities

C. doesn't change too much

D. has more than doubled in the last century

4. Which of the following is NOT a reason why wildlife is returning to the cities?

A. There is plenty of food for wildlife in the city.

B. Wildlife enjoys being watched and fed in the cities.

C.  More and more special living areas have been built for the wildlife.

D. Air and water quality has improved in the cities.