首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A、It has become extinct. B、Its number will increase continually. C、It is taken off the endangered-species list. D、It is America’
A、It has become extinct. B、Its number will increase continually. C、It is taken off the endangered-species list. D、It is America’
admin
2013-10-30
50
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 en-dangered-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. 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.
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. The destruction of their natural homes could be the next DDT, causing eagle numbers to drop quickly.
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、It has become extinct.
B、Its number will increase continually.
C、It is taken off the endangered-species list.
D、It is America’s national symbol.
答案
D
解析
短文开头提到秃鹰是美国的国家象征,在20年前几乎濒临灭绝,故D正确。
转载请注明原文地址:https://kaotiyun.com/show/EGS7777K
0
大学英语四级
相关试题推荐
Forsometimepastithasbeenwidelyacceptedthatbabies--andothercreatures--learntodothingsbecausecertainactsleadto
Forsometimepastithasbeenwidelyacceptedthatbabies--andothercreatures--learntodothingsbecausecertainactsleadto
OpinionpollsrepeatedlytellusthattheonlythingAmericansworryaboutmorethantheenvironmentistheirhealth.Thisis【B1
Accordingtotheauthor,themasonwhytheJapaneseisinfectedgreatlybyEnglishis_____.Whichconclusioncanbedrawnbase
IndustrialRevolutionTheeconomicdevelopmentIndustrialRevolutionwasawidespreadreplacementofmanuallaborbymachines
A、Theyliveinisolatedareas.B、Theyareactiveinvoluntaryservices.C、Theyareinterestedinotherkindsofreading.D、They
Thespeechplatformwas______inthemarketsquare,fromwhichthespeakersaddressedtheassembledcrowd.
A、Shestronglydisagreeswiththeman..B、SheknowsneitherStevennorhisfatheratall.C、ShealsoadmiresSteven’srelations
A、Thenoisesfromthegames.B、Thepossibleenvironmentaldamage.C、Theoverindulgenceoftheirkids.D、Thepotentialdangerof
随机试题
处理晕针时,应采取的首要措施为
房屋拆迁纠纷的裁决应当自收到申请之日起()内作出。
为了减少或避免工程延期事件的发生,监理工程师应做好以下( )工作。
长江公司系上市公司,为增值税一般纳税人,销售或进口货物适用的增值税税率为17%,适用的所得税税率为25%。2×16年年初“递延所得税资产”科目余额为320万元,“递延所得税负债”科目余额为0,其中:因上年职工教育经费超过税前扣除限额确认递延所得税资产20万
第四宇宙速度是指在地球上发射的物体摆脱银河系引力束缚,飞出银河系所需的最小初始速度,但由于人们尚未知道银河系的准确大小与质量,因此只能粗略估算,约为110—120km/s,如充分利用太阳系围绕银心的转速,最低航行速度可为82km/s。而实际上,仍然没有航天
在瓦窑堡会议上,毛泽东指出,“目前时局的基本特点,就是日本帝国主义要变中国为它的殖民地”,中华民族面临着亡国灭种的严重威胁。因此,抗日民族统一战线是有可能建立的,这是因为
程序的3种基本控制结构是()。
可以改变“字段大小”属性的字段类型是
计算机网络按地理范围可分为___________。
MyLifeatRendaIlearnedveryquicklythatbeingateachingassistant(TA)attheUniversityofIowawouldbedifferentfrom
最新回复
(
0
)