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
All through the ages the bat has been a creature of great mystery. Bats have influenced the imagination of the Western World sin
All through the ages the bat has been a creature of great mystery. Bats have influenced the imagination of the Western World sin
admin
2017-02-24
25
问题
All through the ages the bat has been a creature of great mystery. Bats have influenced the imagination of the Western World since the first Spaniards returned from the Americans. They told tales of hairy, winged creatures that flew from caves to feed on the blood of man and animals. The vampire bat, which became a well-known figure in the folk tales of many countries, exists only in the Americans.
The vampire bat is not like the common bat. Its teeth have grown sharper. In the days before Columbus, bat fed on wild animals, but with the introduction of farm animals into the New World by the Spaniards, they were offered a new kind of food. They attacked the cattle which sickened and died and the colonists didn’t know why. It was only in 1908 that farmers in Brazil discovered that the bite of the vampire bat could cause rabies and this was the disease that was killing their cattle. For the first time it was recognized that the bite of a vampire bat could carry the virus of rabies. The cattle of eastern Mexico were especially troubled by this disease.
Many efforts were made by the farmers in Mexico to destroy the bats. They blew up their caves or covered the entrances to caves with nets. All these ways were too slow, too costly, or else didn’t work.
Since they could not remove the bats, the Mexican government and World Health Organization got together in 1952 to develop a cheap dependable supply of the vaccine against rabies at a factory in Mexico. A quarter of a million cattle have been vaccinated at a cost of fifty cents per animal to the owners. In one state alone, death among cattle has fallen from 56% to 1%. Control of the disease in animals seems to be in sight. This will reduce but not destroy the threat that bats may pass the disease to human beings.
Vampire bats like human blood best. Whole villages in Guatemala have disappeared because of the frequency with which bats fed on sleeping children. A study made in Trinidad showed that in thirty houses checked in one village, twenty persons had been bitten by bats. Teachers reported that half of the children coming to school showed signs of having been bitten in the night.
A health research office, which has been collecting information since 1949 about the home and movements of bats, has started work on a book about bats. Various other health organizations also are making new studies. It is hoped that answers to this health problem will soon be found.
What was the effect of the vaccine developed by the Mexican government and WHO in 1952?
选项
A、It was a failure in the experiment
B、It completely destroyed vampire bats
C、It eliminated the virus of rabies altogether
D、It successfully protected the cattle from being infected with rabies
答案
D
解析
细节题。根据题干关键词可定位至文章第四段,A quarter of a million cattle have been vaccinated at a cost of fifty cents per animal to the owners.In one state alone,death among cattle has fallen from 56% to 1%(25万头牛接受了疫苗接种,代价就是每头牛50美分。这样,牛的死亡率从56%下降到了1%。)可知接种疫苗后,牛的死亡率大幅下降。因此,正确答案是D。
转载请注明原文地址:https://kaotiyun.com/show/PnU7777K
0
大学英语六级
相关试题推荐
TrustMe,I’maRobot[A]Withrobotsnowemergingfromtheirindustrialcagesandmovingintohomesandworkplaces,roboticists
A、Womenwouldliketostayathome.B、Peopleweremorefriendly.C、Studentspaidfortheirboard.D、Immigrationwasencouraged.
Oneofthemostcommonimagesofanadvanced,Western-stylecultureisthatofabusy,traffic-filledcity.Sincetheirfirst【B1
Oneofthemostcommonimagesofanadvanced,Western-stylecultureisthatofabusy,traffic-filledcity.Sincetheirfirst【B1
Haveyoueverwantedtotravelbackthroughtimeandseewhatlifewaslikeatthedawnofman?Well,museumscanmakehistory【B
A、Shedoesn’twantthemantocallsoearly.B、Sheurgesthemantocallimmediately.C、Sheencouragesthemantodowhateverhe
A、Beingquietandbookish.B、Sufferingfromstagefright.C、Ignoringpeople’sjudgment.D、Havinganoutgoingpersonality.C选项都是动
随机试题
患者面色萎黄,神疲乏力,少气懒言,自汗,心悸多梦,头晕目眩,舌淡嫩,脉细弱,应考虑为
巨大儿经阴道分娩时新生儿并发症有()
下列何种感染易造成呼吸困难
A、油细胞B、油室C、黏液细胞D、乳汁管E、树脂道党参横切面可见
甲、乙分别为某有限责任公司的自然人股东,后甲在乙知情但不同意的情况下,为帮助妹妹获取贷款.将自有股份质押给银行,乙以甲侵犯其股东权利为由向法院提起诉讼。关于本案.下列哪一判断是正确的?(2011年卷一第12题)
下列关于敏感系数的说法中,不正确的有()。
城市民用天然气的主要成分是()。
Thetitlethatbestexpressestheideasofthispassageis______.Whatistheauthor’sattitudetowardtheinterpretationofne
建立一个表单,表单文件名和表单控件名均为myform_c,表单标题为“职工订单信息”,表单界面如图1-29所示,共有3个文本为职工号(Label1)、姓名(Label2)和性别(Label3)的标签,还有3个对应的文本框(Text1、Text2和Text3
Theworldisplantingavigorousnewcrop:"agro-pessimism",orfearthatmankindwillnotbeabletofeeditselfexceptbywrec
最新回复
(
0
)