2016年北京卷

C

California Condor’s Shocking Recovery

California condors are North America’s largest birds, with wing-length of up to 3 meters. In the 1980s, electrical lines and lead poisoning(铅中毒) nearly drove them to dying out. Now, electric shock training and medical treatment are helping to rescue these big birds.

In the late 1980s, the last few condors were taken from the wild, and there are now more than 150 flying over California and nearby Arizona, Utah and Baja in Mexico.

Electrical lines have been killing them off. “As they go in to rest for the night, they just don’t see the power lines,” says Bruce Rideout of San Diego Zoo. Their wings can bridge the gap between lines, resulting in electrocution(电死) if they touch two lines at once.

So scientists have come up with a shocking idea. Tall poles, placed in large training areas, teach the birds to stay clear of electrical lines by giving them a painful but undeadly electric shock. Before the training was introduced, 66% of set-freed condors died of electrocution. This has now dropped to 18%.

Lead poisonous has proved more difficult to deal with. When condors eat dead bodies of other animals containing lead, they absorb large quantities of lead. This affects their nervous systems and ability to produce baby birds, and can lead to kidney(肾) failures and death. So condors with high levels of lead are sent to Los Angeles Zoo, where they are treated with calcium EDTA, a chemical that removes lead from the blood over several days. This work is starting to pay off. The annual death rate for adult condors has dropped from 38% in 2000 to 5.4% in 2011.

Rideout’s team thinks that the California condors’ average survival time in the wild is now just under eight years. “Although these measures are not effective forever, they are vital for now,” he says. “They are truly good birds that are worth every effort we put into recovering them.”

63.California condors attract researchers’ interest because they ______.

A. are active at night

B. had to be bred in the wild

C. are found only in California

D. almost died out in the 1980s

64.Researchers have found electrical lines are ______.

A. blocking condors’ journey home

B. big killers of California condors

C. rest places for condors at night

D. used to keep condors away

65.According to paragraph 5, lead poisoning ______.

A. makes condors too nervous to fly

B. has little effect on condors’ kidneys

C. can hardly be gotten rid of form condors’ blood

D. makes it different for condors to produce baby birds

66.The passage shows that ______.

A. the average survival time of condors is satisfactory

B. Rideout’s research interest lies in electric engineering

C. the efforts to protect condors have brought good results

D. researchers have found the final answers to the problem

答案解析：

63. D

根据文中“In the 1980s, electrical lines and lead poisoning(铅中毒) nearly drove them to dying out.”可知，在20世纪80年代，电线和铅中毒几乎使加州神鹫灭绝，所以加州神鹫吸引了研究人员的兴趣，是因为它们在20世纪80年代几乎灭绝，所以选D。更多真题请微信搜索英语巴士小程序。

64. B

根据文中“Electrical lines have been killing them off.”以及“Their wings can bridge the gap between lines, resulting in electrocution(电死) if they touch two lines at once.”可知，电线一直在导致加州神鹫死亡，它们飞翔时翅膀可能会搭在电线上，同时触碰两根电线就会被电死，这说明电线是加州神鹫的大杀手，所以选B。

65. D

根据文中“This affects their nervous systems and ability to produce baby birds, and can lead to kidney(肾) failures and death.”可知，铅中毒会影响加州神鹫的神经系统和繁殖幼鸟的能力，还会导致肾衰竭和死亡，所以铅中毒使得加州神鹫繁殖幼鸟变得困难，所以选D。

66. C

根据文中“Before the training was introduced, 66% of set - freed condors died of electrocution. This has now dropped to 18%.”以及“The annual death rate for adult condors has dropped from 38% in 2000 to 5.4% in 2011.”可知，在采取相关保护措施后，因触电死亡的加州神鹫比例下降，成年神鹫的年死亡率也大幅下降，这说明保护加州神鹫的努力取得了良好的效果，所以选C。