5、The US government has announced plans to list polar bears as a threatened species because of concerns that the ice where they live is melting. But as the BBC’s Owen Clegg reports, the US plans are also important for other reasons.

It’s estimated（估計(jì)）that there are no more than twenty-five thousand polar bears living in the wild, and this number could go down by a large amount as the floating ice upon which the bears survive melt away. Now, without admitting the cause of this melt, the US Fish and Wildlife Services are reviewing the bear’s living conditions.

   That action is being taken at all, and marks an important change for the Bush administration; for the first time, it may be forced to acknowledge a link between global warming and its effect on a species. Such a conclusion by an unwilling Bush administration could force far wider changes in Washington’s policy towards the environment.

   This review only came about after a union of environmental groups brought a legal case against the government to take action. Environmentalists, like David Doniger, believe that by calling on the protections of the Endangered Species Act, the US government may finally be forced to cut back on its sending out greenhouse gases:

   “It is a very important thing today to have the Bush administration notice that global warming is threatening the existence of the polar bear. Now, it’s up to the administration to do something to stop the global warming that’s threatening the polar bear.” ( David Doniger)

   The United States is the world’s largest emitter（發(fā)放者）of greenhouse gases which are blamed for trapping heat from the sun and changing the earth’s climate. Since taking office in 2001, President Bush has refused to make the link with global warming, but the bad, serious situation of the polar bear may force that position to change.

 

46. What is the direct reason for the polar bear to become endangered?

A. It is that the floating ice upon which they survive melts away.

B. It is that more greenhouse gases have been sent out.

C. It is because of the global warming.

D. It is because of no protection of their living conditions.

47．What is the significance of US Fish and Wildlife Services’ reviewing the bear’s living conditions?

A. It brought a legal case against the government.

B. It marks an important change for the Bush administration.

C. It is a conclusion by a Bush administration.

D. It makes the protections of the Endangered Species Act possible.

48. What is David Doniger’s comment on the review of the bear’s living conditions?

A. The US government may finally be forced to notice that global warming is totally caused by them.

B. The US government may finally be foced to stop sending out greenhouse gases.

C. The US government may finally be forced to do something to stop the global warming that’s threatening the polar bear.

D. The US government may finally be forced to change the earth’s climate.

49. Which country has been sending out the largest number of greenhouse gases according to the passage?

A. China.                   B. Britain.             C. The United States.          D. Not mentioned.

50. Which of the following is implied in the passage?

A. The Bush administration has long acknowledged that global warming is threatening the existence of the polar bear.

B. Bush administration has done a lot to control the sending-out of greenhouse gases.

C. The greenhouse gases have no links with the melting polar ice and the decreasing number of the polar bears.

D. The US government should be partly responsible for the melting polar ice and the decreasing number of the polar bears.