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、There are 250 million plants eaten by insects. B、There are fewer plants than 250 million years ago. C、They have their way of g
A、There are 250 million plants eaten by insects. B、There are fewer plants than 250 million years ago. C、They have their way of g
admin
2013-01-20
32
问题
Scientists have observed that plants themselves produce many poisonous chemicals for defense against insects. But insects have developed ways of dealing with them and,in fact,have been eating plants for about 250 million years.Now insects are using these same mechanisms to deal with man-made poisons-insecticide.This is why resistance of insects to insecticide has developed so rapidly.What should be done?Scientists studyilg the problem suggest that farmers use less insecticide.At the moment,famlers regularly spray crops as a precaution against problems that are caused by large numbers of pests.They should,instead,spray only where pests have actually been seen.Secondly,farmers could use a combination of two or three jnsecticide at once.To survive,the insects would need to become resistant to two or more poisons at the same time.The most surprising suggestion,perhaps,perhaps,is that,at certain times of the year,famers should actually try to attract new insects onto the crops they are trying to protect.The new insects will mate with those which survived from a certain kind of insecticide and will lessen the latter’s resistance to it.
Scientists hope that these and other measures will postpone the day when farmers and scientists will have to stand by while new super bugs which may be resistant to all our poisons invade our farms and devour our crops.
选项
A、There are 250 million plants eaten by insects.
B、There are fewer plants than 250 million years ago.
C、They have their way of guarding against insects.
D、They have a better immune system than before.
答案
C
解析
短文开头就说到,科学家发现庄稼自身可以产生许多有害的化学物质来抵御昆虫的侵害,即庄稼自有抵制昆虫侵害的方法,C与此含义相符,故正确。
转载请注明原文地址:https://kaotiyun.com/show/Lbu7777K
0
大学英语四级
相关试题推荐
Averyimportantworldproblemistheincreasingnumberofpeoplewhoactuallyinhabitthisplanet.Thelimitedamountoflanda
A、Changethelawsonlimitingruralfarms.B、CarryouttheprojectAlleycatAcresinSeattle.C、InviteschoolgroupstoAlleycat
Chemistrydidnotemergeasascienceuntilafterthescientificrevolutionintheseventeenthcenturyandthenonlyratherslow
Forthispart,youareallowed30minutestowriteashortessayentitledWeShouldn’tTotallyTurntotheInternet.Youshould
Distancelearninghasmovedfarawayfromthetraditionalcorrespondencecourse,aimedattheindividualstudentworking【S1】____
Researchershaveidentified1.4millionanimalspeciessofar—andmillionsremaintobediscovered,named,andscientificallyd
Researchsuggeststhatparentalinvolvementinschoolisvitaltoachild’sacademicsuccess.However,ifyou’reasingleparent
AmongthecriticismsoftheObamaadministration’sbankrescueproposalisthatthegovernmentwillprovideupto$1trillionin
1.2millionroaddeathsworldwideoccureachyear,plusafurther50millioninjuries.Toreducecarcrashrate,muchresearchn
Wisebuyingisapositivewayinwhichyoucanmakeyourmoneygofurther.The【C1】______yougoaboutpurchasinganarticleora
随机试题
近代以来中华民族最伟大的梦想是()
随着生产力水平的提高,第二产业逐渐占优势比重,我们称之为()
在幼儿教育机构中,()是对学前儿童进行语言教育的基本形式。
以下给出的事件中,无须异常处理程序进行中断处理的是()。
下列关于黄炎培的“职业教育的地位”的思想表述错误的是
非公有制经济包括个体经济、私营经济、外商独资经济、混合所有制经济中的非公有制成分等。鼓励、支持、引导非公有制经济发展的原因是
设=2,其中a2+c2≠0,则必有()
设函数f(x)在闭区间[a,b]上连续,且f(x)>0,则方程=0在开区间(a,b)内的根有
InterculturalCommunicationProblemsandSolutionsI.InterculturalCommunicationProblemsA.Stereotyping—Definition:aselec
Theextentandlimitsofape(猿)intelligenceisahotareainscience,butmostoftheresearchhasfocusedoncognition.Nowa
最新回复
(
0
)