首页
登录
职称英语
[originaltext]America’s national symbol--the Bald Eagle--almost went extinct 20
[originaltext]America’s national symbol--the Bald Eagle--almost went extinct 20
游客
2023-09-07
69
管理
问题
America’s national symbol--the Bald Eagle--almost went extinct 20 years ago. But it has made a comeback. In fact, the US Fish and Wildlife Service is considering the possibility of taking it off the endangered species list. Once, more than 50 000 pairs of bald eagles nested across the country. But by 1960, that number had fallen below 400. The chief killer was the widely used DDT. Fish soaked up DDT died and were washed up on shores where bald eagles feasted on them. (29)DDT prevented eagle eggshells from thickening. The shells became so thin that they shattered before the babies hatched. Fortunately, in 1972, a law was passed to ban DDT, which saved the bald eagle from total wipeout. (30)And since then, wildlife biologists have reintroduced bald eagle eggs from Canada to America. The result was that last year US bird watchers counted 11 610 bald eagles in the country. If it were dropped from the endangered list, the bald eagle would still be a threatened species. That means the bird would continue to get the same protection--no hunting allowed, and no disturbing of nests. (31 ) But bald eagles still face tough times. The destruction of their natural homes could be the next DDT causing eagle numbers to drop quickly.
选项
A、It limited their supply of food.
B、It made their eggshells too fragile.
C、It destroyed many of their nests.
D、It killed many baby bald eagles.
答案
B
解析
事实细节题。原文提到,DDT使得蛋壳变得很薄,在小鹰孵化之前就碎了。由此可见DDT对秃鹰的危害是B)。
转载请注明原文地址:http://tihaiku.com/zcyy/2993451.html
相关试题推荐
[originaltext]Inaway,allofusareonaspaceship,theplanetEarth.We
[originaltext]Inaway,allofusareonaspaceship,theplanetEarth.We
[originaltext]Inaway,allofusareonaspaceship,theplanetEarth.We
[originaltext]Oneofthereasonsforoursuccessasaspeciesisourabilit
[originaltext]M:Thinkaboutit,Mary.Throughtelecommunicationinformationtr
[originaltext]M:Thinkaboutit,Mary.Throughtelecommunicationinformationtr
[originaltext]W:HowwasyourtriptotheGrandCanyon?M:Itwasexcellent!We
[originaltext]W:HowwasyourtriptotheGrandCanyon?M:Itwasexcellent!We
[originaltext]W:Areyousureyou’vecorrectedallthetypingerrorsinthispa
[originaltext]W:Areyousureyou’vecorrectedallthetypingerrorsinthispa
随机试题
RollingStonesTherockgroup,mem
InwhatfieldmighttheexampleofHelenKellerbefit?[br][originaltext]
【B1】[br]【B15】A、chooseB、changeC、distinguishD、compareC词义辨析及介词搭配题。choose指选择;c
[audioFiles]audio_eusm_j50_001(20082)[/audioFiles]A、Cousins.B、Auntandnephew.
Ihavecertainlyseenlotsofchangesinmylifetime!Ilookaroundmyhomeand
Earthquakesmayrightlyberankedasoneofthemostdevastatingforcesknow
某公司2015年度资产负债表中,货币资金为600亿元,应收账款为200亿元,应收
奥苏贝尔强调的有意义的接受学习是指学习材料有意义。 ()
封闭式提问一般用于()。 (A)澄清事实真相(B)叙述情绪反应 (C)剖析
男,68岁。2个月前因妻子生病住院出现焦虑不安,情绪低落,兴趣减退,失眠早醒,日
最新回复
(
0
)