首页
登录
职称英语
[originaltext] America’s national symbol—the Bald Eagle—almost went extinct
[originaltext] America’s national symbol—the Bald Eagle—almost went extinct
游客
2023-09-09
40
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,故本题选择B项。
转载请注明原文地址:https://tihaiku.com/zcyy/2997720.html
相关试题推荐
[originaltext]IntheUSwehavefreecompulsorypubliceducationforallch
[originaltext]IntheUSwehavefreecompulsorypubliceducationforallch
[originaltext]W:Hey,Joe.What’sallthistalkaboutabenefitwalkathonthis
[originaltext]W:Hey,Joe.What’sallthistalkaboutabenefitwalkathonthis
[originaltext]M:Hi,Jane.Howisyourvacation?W:Terrific!IwenttoWashing
[originaltext]Inwesternculturemusicisregardedasgoodbybirth,andso
[originaltext]Inwesternculturemusicisregardedasgoodbybirth,andso
[originaltext]Theworld’ssmartadolescenceinmathematicsandscienceare
[originaltext]Theworld’ssmartadolescenceinmathematicsandscienceare
[originaltext]Aristotle,fileGreekphilosopher,summedupthefourchiefq
随机试题
GreenPowerYou’veinsulatedtheattic,installedtriple-glazed
Mytopictodayishowtoaddresstheproblemofhungerandstarvationwhich
AsagroupofyoungAfricanimmigrantsstrugglestoadapttolifeintheUni
下列选项中,对于“高跷”表述不正确的是:()A.汉族民间舞蹈之一,也叫“高跷秧
研究表明,进入雷云的宇宙射线,使得雷云中的空气产生电离,进而便在周围产生许多悬浮
辨析:义务教育又称强迫教育。
燥邪伤人引发的主要症状有A.口鼻干燥 B.皮肤干涩 C.毛发不荣 D.干咳
血浆游离胆固醇升高的可能原因是( )。A.胰脂酶缺乏 B.HMG-CoA还原
单位或者个人有意愿实施开放许可的专利的,应当书面征求专利权人同意,并支付许可使用
它利用声波通道截面的突变,使沿管道传递的某些特定频段的声波反射回声源,从而达到消
最新回复
(
0
)