首页
登录
职称英语
Scientists have discovered that plants themselves produce many poisonous che
Scientists have discovered that plants themselves produce many poisonous che
游客
2024-06-16
59
管理
问题
Scientists have discovered that plants themselves produce many poisonous chemicals for (36)______ against insects. But insects have developed ways of (37)______ with them and, in fact, have been eating plants for about 250 million years. Now insects are using these same (38)______ to deal with man-made poisons—insecticides. This is why (39)______ of insects to insecticides has developed so (40)______.
What should be done? Scientists studying the problem suggest that farmers use less insecticides. At the moment, farmers (41)______ spray crops as a (42)______ against problems that are caused by large number of pests. They should, instead, spray only where pests have actually been seen. Secondly, farmers could use a (43)______ of two or three insecticides at once. (44)____________.
The most surprising suggestion, perhaps, is that at certain times of the year, (45)____________. The new insects will mate with those which survived from a certain kind of insecticide and will lessen the latter’s resistance to it.
(46)____________ , which may be resistant to all poisons invade our farms and devour our crops.
[br]
Scientists have discovered 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—insecticides. This is why resistance of insects to insecticides has developed so rapidly
What should be done? Scientists studying the problem suggest that farmers useless insecticides. 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 insecticides at once. To survive, the insects would need to become resistant to two or more insecticides at the same time.
The most surprising suggestion, perhaps, is that at certain times of the year, farmers should actually try to attract insects onto the crops they are trying to protect. The new insects will mate with those which survived from a certain kind of insecticide anti will lessen the latter’s resistance to it.
Scientist 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 poisons invade our farms and devour our crops.
选项
答案
rapidly
解析
转载请注明原文地址:https://www.tihaiku.com/zcyy/3636506.html
相关试题推荐
ValmontIndustries,Inc.isaleadingproduceranddistributorofproduct
ValmontIndustries,Inc.isaleadingproduceranddistributorofproduct
Whathavepeoplediscoveredabouthobbies?Hobbiescanbeprofitableand_______
Whathavepeoplediscoveredabouthobbies?Hobbiescanbeprofitableand_______
Whathavepeoplediscoveredabouthobbies?Hobbiescanbeprofitableand_______
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Bytheendoflastmonth,ourfactory(produce)________3,000motors.hadproduc
Thelearnedthinkthemselvessuperiortothecommonherd.A、有学问的人认为他们比普通群众高明。B、知
随机试题
Moreandmoreemployersaredemandingthatworkerswhosmokeorareoverweig
Helendidknowsomethings,though.Mostoftheseshehadlearnedfromhers
A.疲乏无力 B.多尿而频 C.消谷善饥 D.烦渴引饮 E.口干舌燥消渴
A.维生素A B.维生素B C.维生素B D.维生素C E.维生素D脚气
下列各项中标点符号使用不正确的一项是( )。A.龙应台认为,欧洲的现代与传统之
简要介绍终身教育的主张。
为了提高知识理解水平,常用的直观形式有实物直观、()、言语直观。
牙源性角化囊性瘤的内容物是哪种性质的A:白色凝乳状物质 B:无色透明黏稠液体
下列不得作为税务行政复议定案依据的有()。A.以偷拍方式获取侵害他人合法权
诊断子宫性闭经的依据是A.注射黄体酮有撤退性出血 B.注射黄体酮无撤退性出血
最新回复
(
0
)