首页
登录
职称英语
[originaltext] America’s national symbol, the bald eagle, almost went extinc
[originaltext] America’s national symbol, the bald eagle, almost went extinc
游客
2024-05-14
30
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 U. S. 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. 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. And since then, wildlife biologists have reintroduced bald eagles from Canada to America. The result was that last year U. S. birdwatchers 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.
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 to fragile.
C、It destroyed many of their nests.
D、It killed man baby bald eagles.
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3597698.html
相关试题推荐
[originaltext]Manylargecitiesareanythingbutbeautiful.Streetsarelit
[originaltext]Ifacityeverneededtallbuildingsinahurry,itwasChica
[originaltext]Ifacityeverneededtallbuildingsinahurry,itwasChica
[originaltext]M:Ijustcan’tconcentratehereintheflat.(19)Yousee,Arthu
[originaltext]M:Ijustcan’tconcentratehereintheflat.(19)Yousee,Arthu
WhatdoAmericanparentsexpecttheirchildrentoacquireinschool?[br]Emerso
WhatdoAmericanparentsexpecttheirchildrentoacquireinschool?[br]Wecan
OnDecember25,2000,manypeopleacrossNorthAmericareceivedarareChri
OnDecember25,2000,manypeopleacrossNorthAmericareceivedarareChri
OnDecember25,2000,manypeopleacrossNorthAmericareceivedarareChri
随机试题
Thehealth-careeconomyisrepletewithunusualandevenuniqueeconomicrel
Theymaybelivid(愤怒)withtheirleaders,painedbytheirplaceintheworld
Manyatime______themnottodoso.A、wehavewarnedB、dowehavewarnedC、havew
[img]2019m9x/ct_eyyjsdz2019j_eyyjsdreadb_0172_201909[/img]Allergyhasbecome
甲公司是深圳交易所创业板上市公司,2017年5月,甲公司拟聘请孙某作为该公司的独
患儿,10岁。发热,耳下腮部漫肿疼痛。除内服药外,宜配合使用的外治法是A.附子
下列不属于中央银行的职能的是()。A:货币发行 B:金融监管 C:信用创造
已知盐酸普鲁卡因1%水溶液的冰点降低值为0.12℃。欲配置2%的盐酸普鲁卡因水溶
与其他金融工具相比较,开放式基金是一种()。A:收益凭证B:信用凭证C:受益
牙周病治疗常用的局部冲洗药物有A.3%过氧化氢溶液 B.碘伏溶液 C.碘甘油
最新回复
(
0
)