单选题
One thing the tour books don't tell you about London
is that 2.000 of its residents are foxes. As native as the royal family, they
fled the city about centuries ago alter developers and pollution moved in. But
now that the environment is cleaner, the foxes have come home, one of the many
wild animals that have moved into urban areas around the world.
"The number and variety of wild animals in urban areas is increasing," says
Gomer Jones, president of the National Institute for Urban Wildlife, in
Columbia, Maryland. A survey of the wildlife in New York's Central Park last
year tallied the species of mammals, including muskrats, shrews and flying
squirrels. A similar survey conducted in the 1890s counted only five species.
One of the country's largest populations of raccoons (浣熊) now lives in
Washington D.C., and moose (驼鹿) are regularly seen wandering into Maine towns.
Peregrine falcons (游隼) dive from the window ledges of buildings in the largest
U.S. cities to prey on pigeons. Several changes have brought
wild animals to the cities. Foremost is that air and water quality in many
cities has improved as a result of the 1970s' pollution-control efforts.
Meanwhile, rural areas have been built up, leaving many animals on the edges of
suburbia. In addition, conservationists have created urban wildlife
refuges. The Greater London Council last year spent $750,000 to
buy land and build 10 permanent wildlife refuges in the city. Over 1,000
volunteers have donated money and cleared rabble from derelict lots. As a
result, pheasants now strut in the East End and badgers scuttle across lawns
near the center of town. A colony of rare house martins nests on a window ledge
beside Harrods, and one evening last year a fox was seen on Westminster Bridge
looking up at Big Ben. For peregrine falcons, cities are
actually safer than rural cliff dwellings. By 1970 the birds were extinct east
of the Mississippi because the DDT had made their eggs too thin to support life.
That year, ornithologist Tom Cede of Cornell University began rising the birds
for release in cities, for cities afforded abundant food and contained none of
the peregrine's natural predators. "Before they were
exterminated, some migrated to cities on their own because they had run out of
cliff space," Cade says. "To peregrines, buildings are just like cliffs." He has
released about 30 birds since 1975 in New York, Baltimore, Philadelphia and
Norfolk, and of the 20 pairs now living in the East, half are urbanites. "A few
of the young ones have gotten into trouble by falling down chimneys and crashing
into window-glass, but overall their adjustment has been successful."
单选题
The first paragraph suggests that ______.
A. environment is crucial for wildlife
B. tour books are not always a reliable source of information