2013-06-12 20:49:28 来源:
Of all the continents, the most drastic reduction in wildlife has occurred in North America, where the transition from a rural to a highly industrialized society has been most rapid. Among the victims are birds, mammals, and fish. We will never again see the passenger pigeon or the eastern elk. They have been wiped out. Of many other species, only a few representatives still survive in the wild. The U. S. Department of the Interior has put no fewer than 109 species on the endangered species list. (An endangered species is one with poor prospects for survival and in need of protection. ) This list includes everything from the timber wolf to the whooping crane. Even the bald eagle, our national symbol, is threatened.
Animals that kill other game for food are called predators. The predators include the wolf, mountain lion, fox, bobcat, and bear. Attack against these animals began with the arrival of the first European settlers, who wished to protect their livestock. Eventually, a reward was offered to hunters for every predator that was killed. This reward is called a bounty.Ironically, the Federal government is the chief founder of predator-control programs.
The settlers also brought in their Old World fears and superstitions concerning predators. Whether preying (捕食) on livestock or not, predators were shot on sight. This attitude continues to this day for coyotes, eagles, foxes, mountain lions, and bobcats, and is largely responsible for placing the eastern timber wolf, grizzly bear, and bald eagle on the endangered species list.
Yet every animal, including the predator, has its place in nature's grand design. Predators help maintain the health of their prey speciesby eliminating the diseased, young, old and injured. Predators like the mountain lion and the wolf help to keep the deer herds healthy. Occasional loss of livestock must be weighed against the good these animals do in maintaining the balance of nature.
1. In North America, the number of wild animals has reduced most greatly mainly • 112 • because_______.
A. the birds, mammals and fish there are most predators
B. the development there has been at the highest pace
C. only a few species still live in the world
D. many species have been put on the endangered species list
2. The first European settlers killed predators chiefly in order to_______.
A. eat their meat
B. protect themselves
C. please the Federal government
D. protect their livestock
3. Some animal species are in danger of disappearing altogether from the earth as a result of_______.
A. people's superstitious attitude
B. people's dislike of some animals, such as bald eagle
C. people's hunting games
D. the self-killing of the predators
4. Bounty hunters are people who_______.
A. take care of wilderness areas
B. preserve our wildlife
C. kill meat-eating animals for money
D. work in the fund of predator-control programs
5. According to the writer, even if the meat-eating animals sometimes caused losses of livestock, man should_______.
A. estimate the value of predators
B. compare the losses with the benefits of predators
C. keep the balance of nature
D. raise more livestock
1. B 2. D 3. A 4. C 5. B