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
44
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、They found ways to speed up the reproduction of bald eagles.
B、They developed new types of feed for baby bald eagles.
C、They explored new ways to hatch baby bald eagles.
D、They brought in bald eagles from Canada.
答案
D
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3597699.html
相关试题推荐
[originaltext]Manylargecitiesareanythingbutbeautiful.Streetsarelit
[originaltext]Manylargecitiesareanythingbutbeautiful.Streetsarelit
[originaltext]Ifacityeverneededtallbuildingsinahurry,itwasChica
[originaltext]Ifacityeverneededtallbuildingsinahurry,itwasChica
[originaltext]M:Ijustcan’tconcentratehereintheflat.(19)Yousee,Arthu
[originaltext]M:Ijustcan’tconcentratehereintheflat.(19)Yousee,Arthu
[originaltext]M:Ijustcan’tconcentratehereintheflat.(19)Yousee,Arthu
WhatdoAmericanparentsexpecttheirchildrentoacquireinschool?[br]Emerso
OnDecember25,2000,manypeopleacrossNorthAmericareceivedarareChri
OnDecember25,2000,manypeopleacrossNorthAmericareceivedarareChri
随机试题
[originaltext]Microsofthasbeenforcedtoacknowledgethatasubstantialn
HongKonghastakenoverfromTokyoastheworld’smostexpensivecity,acco
根据建设工程的要求,查明、分析、评价建设场地的地质地理环境特征和岩土工程条件,编
A. B. C. D.
被称为\"基因卫士\"的抑癌基因是A.APC B.Rb C.P D.DCC
A.超声检查 B.选择性肝动脉造影检查 C.磁共振成像 D.肝穿刺针吸细胞
A.0 B.1 C.2 D.3
假如你是我单位办公室的工作人员,单位决定在两周后召开下属企业党委书记工作会议,探
下列哪些欧式期权可以采用B-S-M模型进行定价?()A.利率期权 B.货
A.助阳化气 B.透疹止痒 C.宣肺平喘 D.燥湿止带 E.和中化湿浮萍
最新回复
(
0
)