首页
登录
职称英语
[originaltext] Scientists have observed that plants themselves produce many
[originaltext] Scientists have observed that plants themselves produce many
游客
2024-02-17
40
管理
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:http://tihaiku.com/zcyy/3459111.html
相关试题推荐
[originaltext]Ofallthestarsthesunisthenearesttotheearth.Million
[originaltext]Ofallthestarsthesunisthenearesttotheearth.Million
[originaltext]Manychangesaretakingplaceinthewayinwhichmenandwom
[originaltext]Pete:HeyMarkus.IhaveaquestionI’dliketoaskyou.Markus:
[originaltext]W:Whodoyouthinkshouldgetthejob?HowaboutMr.Becket?M:
[originaltext]W:Whodoyouthinkshouldgetthejob?HowaboutMr.Becket?M:
[originaltext]W:Whodoyouthinkshouldgetthejob?HowaboutMr.Becket?M:
[originaltext]W:Whodoyouthinkshouldgetthejob?HowaboutMr.Becket?M:
[originaltext]Togetadriver’slicense,youmusttakeaseriesoftests.T
[originaltext]Togetadriver’slicense,youmusttakeaseriesoftests.T
随机试题
Athrongofbeardedmen,insad-coloredgarmentsandgraysteeple-crownedhats
Hecanonlyblamehimselfforfailingtheexam.He______harderduringtheyear
______(不管你出了多少错),youarestillaheadofthosewhowon’ttry.Nomatterhowmany
Lookingbackonmychildhood,Iamconvincedthatnaturalistsarebornandn
A—SupplyagreementJ—PortofarrivalB—TradeagreementK—PromptshipmentC—Long-
设函数y=e2x,则dy=_______.
热熔型涂料存在的不足有()。A.大量耗能 B.重涂施工难度大 C.造价高
某住宅楼采暖干管平面如图,采用焊接钢管。公称尺寸≤DN32,用螺纹连接;公称尺寸
下列哪项检查结果表示乙型肝炎的传染力最强A.抗-HBs(+)、抗-HBc(+)、
张婆婆在老伴去世后一直一个人住在乡下,她的儿女都生活在城市,无法照顾她,于是就委
最新回复
(
0
)