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
2023-09-03
92
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、Pollution of the environment.
B、A new generation of pest killers.
C、Over-killing by hunters.
D、Destruction of their natural homes.
答案
D
解析
转载请注明原文地址:http://tihaiku.com/zcyy/2981434.html
相关试题推荐
[originaltext]Theyearis2094.Ithasbeenannouncedthatacometisheadingt
[originaltext]Theyearis2094.Ithasbeenannouncedthatacometisheadingt
[originaltext]Facialexpressionscarrymeaningthatisdeterminedbysituat
[originaltext]Facialexpressionscarrymeaningthatisdeterminedbysituat
[originaltext]W:DoestheMotorVoterLawcoverallthestates?M:No.W:Which
[originaltext]W:DoestheMotorVoterLawcoverallthestates?M:No.W:Which
[originaltext]M:MissHanson,thankyouforsendingmethisnote.I’msorryto
[originaltext]M:MissHanson,thankyouforsendingmethisnote.I’msorryto
[originaltext]M:MissHanson,thankyouforsendingmethisnote.I’msorryto
[originaltext]M:MissHanson,thankyouforsendingmethisnote.I’msorryto
随机试题
Whatweneedforthisjobissomeonewitha(n)______andenquiringmindwhowill
A.石斛、芦根 B.金银花、连翘 C.石膏、郁金 D.黄芩、桑白皮 E.
经济纠纷:是指在经济活动中,双方当事人就权利与义务关系所发生的争执。下列不属于经
岩溶发育的必要条件之一是( )。A.岩层有褶皱和断层 B.存在厚层、质纯、粒
根据症状和体征提示有胸腔积液时,要确定是否有胸腔积液应首选的检查A.胸片 B.
波动率增加将使行权价格附近的Gamma减小。()
案例三: 一般资料:求助者,男性,43岁,公务员。 案例介绍:求助者的女儿今
胰酶临床应用注意包括A.在微碱性环境下助消化效果最好 B.多制成肠溶片剂,且不
投资者在选择银行理财产品时,应该留意的内容有( )。A.购买起点 B.预期年
甲公司职工汪某非因工负伤住院治疗。已知汪某月工资3800元,当地最低月工资标准为
最新回复
(
0
)