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
2024-01-30
55
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 studying the problem suggest that farmers use less insecticide. At the moment, farmers 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 insecticide 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, is that, at certain times of the year, farmers 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.
19 What does the speaker say about plants?
20 What is mentioned as one of the suggestions raised by scientists?
21 What is the most surprising suggestion scientists give?
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,科学家发现植物自身可以产生许多有害的化学物质来抵御昆虫的侵害,即植物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://tihaiku.com/zcyy/3405916.html
相关试题推荐
[originaltext]Anewstudyfoundthat43percentofboyandgirlparticipant
[originaltext]Anewstudyfoundthat43percentofboyandgirlparticipant
[originaltext]Peoplewithbiggerbrainstendtoscorehigheronstandardte
[originaltext]Peoplewithbiggerbrainstendtoscorehigheronstandardte
[originaltext]Iliveinasmallvillageinthecountry.MywifeandIrunt
[originaltext]W:Goodafternoon,Mr.Burke.Didyouhaveagoodlunch?M:Yes,
[originaltext]W:Goodafternoon,Mr.Burke.Didyouhaveagoodlunch?M:Yes,
[originaltext]W:Goodafternoon,Mr.Burke.Didyouhaveagoodlunch?M:Yes,
[originaltext]M:Hello.Ineedtotalkwithsomeoneaboutmydriver’slicense.
[originaltext]M:Hello.Ineedtotalkwithsomeoneaboutmydriver’slicense.
随机试题
IntheUnitedStates,itisnotcustomarytotelephonesomeoneveryearlyin
SPICE:FLAVOR::A、splint:limbB、block:vimC、copper:alloyD、symmetry:balanceE、mo
WhichAirport?Thechoiceofwheretoflyfromhasne
[originaltext]W:Youlookawful.Didyouwalkallthewayfromthebusstopin
供应链是围绕核心企业,通过对信息流、物流、资金流的控制,将供应商、制造商、分销商
党的十九大报告指出,必须多谋民生之利、多解民生之忧,在发展中补齐民生短板、促进社
主要用四唑氮蓝染料(NBT)试验诊断的疾病是A.固有免疫缺陷 B.严重联合免疫
关于作业速率的说法,错误的是( )。A.人的生理上有一个最有效或最经济的作业速
在设计和实施审计程序应对重大错报风险时,下列各项中,体现保持职业怀疑的是(
甲企业与乙企业相邻,甲企业发生火灾后乙企业立即给予支援,最终在公安消防队的带领下
最新回复
(
0
)