首页
登录
职称英语
[originaltext][16] America’s national symbol, the bald eagle, almost went extin
[originaltext][16] America’s national symbol, the bald eagle, almost went extin
游客
2024-01-27
43
管理
问题
[16] 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 ate them up. [17] DDT caused eagle eggshells to weaken and crack. The shells became so thin that they cracked before the babies emerged from the eggs. The eagle had no defense against DDT. [18] Fortunately, in 1972, a law was passed to ban DDT, which saved the bald eagle from dying out. 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. [19] The destruction of their natural homes could be the next DDT, causing eagle numbers to drop quickly.
Questions 16 to 19 are based on the passage you have just heard.
16. What do we learn about the bald eagle?
17. How did DDT affect the bald eagles?
18. What has been done to prevent bald eagles from dying out?
19. According to the passage, what will cause the number of bald eagles to decline?
选项
A、DDT.
B、The disturbing of nests.
C、Hunting.
D、The destruction of their natural homes.
答案
D
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3399983.html
相关试题推荐
[originaltext]Someyearsago,anAmericanpolicemanfoundawomanlyingnea
[originaltext]Someyearsago,anAmericanpolicemanfoundawomanlyingnea
[originaltext][16]America’snationalsymbol,thebaldeagle,almostwentextin
[originaltext]WhenUSspacewomanJoanHigginbothamisnotflyingandworking
[originaltext]BeforeWorldWarn,wespentoursummerholidaysinHungary.
[originaltext]BeforeWorldWarn,wespentoursummerholidaysinHungary.
[originaltext]BeforeWorldWarn,wespentoursummerholidaysinHungary.
[originaltext]Mrs.Joneswasovereighty,butshestilldroveheroldcarlike
[originaltext]Mrs.Joneswasovereighty,butshestilldroveheroldcarlike
[originaltext]Mrs.Joneswasovereighty,butshestilldroveheroldcarlike
随机试题
Threepassions,simplebutoverwhelminglystrong,havegovernedmylife:thelon
ThecityfinallywonapprovalforalimitedspeedcameraprograminJuneaft
比利时的()在1829年提出了“视觉滞留”原理,根据这一原理发明了锯齿形“诡盘
患者,女性,37岁,急诊入院,主诉半小时前突然感到头晕目眩,呼吸困难,心前区疼痛
《变电评价管理规定第29分册变电站运维管理评价细则》:关于竣工验收(技改工程),
与城市本地学生相比,农民工随迁子女的学习基础大多较差,家庭教育缺失,对学习缺乏主
旅游区在开发建设之前,首先应编制()。[2011年真题]A.控制性详细规
员工招聘的作用是()。A.通过员工招聘,可以为空缺职位找到合适的人选 B.通
放射性131IA.抑制甲状腺激素生物合成 B.首先抑制甲状腺激素释放,也抑制其
某项目建设期为2年,建设期内每年初贷款1000万元,年利率为8%。若运营期前5年
最新回复
(
0
)