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
55
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:https://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
LanguageFamiliesThereareover【1】languagesth
Inadditiontovisibletrade,whichinvolvestheimportandexportofmercha
[originaltext]W:ProfessorMarnes,Iwonderifyoucanfillmeinonyourlectu
根据《安全生产法》的规定,安全生产监督管理部门要求,被审查、验收的单位购买其指定
根据《招标投标法实施条例》,投标保证金不得超过()。A.招标项目估算价的2%
审查应付票据,发现其中两份由于资金短缺未能按期支付,但账面记录未作调整,审计人员
血中Hb实际结合的氧量是A.氧含量 B.氧容量 C.氧和Hb的亲和力 D.
人身保险以人的生命或身体为保险标的,它的主要险种包括()。A.人身伤害责任保险
墙体节能工程使用的材料、产品进场时,应对其下列()性能进行复验。A.保温隔
在质量管理过程中,排列图法可以发挥的作用有( )。A.通过抽样检查或检验试验查
最新回复
(
0
)