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
2023-09-16
71
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
combination
解析
转载请注明原文地址:https://www.tihaiku.com/zcyy/3020243.html
相关试题推荐
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Scientistsfindthathard-workingpeoplelivemuchlongerthanaveragemena
Bytheendoflastmonth,ourfactory(produce)______3000motors.hadproduced本题考
Scientistsshouldbekept_____ofthelatestdevelopmentsintheirresearcharea
Thescientistswantedtokeeppeople_____aboutthebreakthroughintheirexper
Whathavepeoplediscoveredabouthobbies?Hobbiescanbeprofitableand______.
Whathavepeoplediscoveredabouthobbies?Hobbiescanbeprofitableand______.
Whathavepeoplediscoveredabouthobbies?Hobbiescanbeprofitableand______.
Scientistshavedonealotofstudytoshowthatpraiseisfar(effective)______
随机试题
"Home,sweethome"isaphrasethatexpressesanessentialattitudeintheU
[originaltext]Iwillletyouknowthatthere’sabigdifferencebetweenund
[img]2014m9s/ct_etoefm_etoeflistz_0508_20149[/img][br]Whydoesthewomantell
某县财政局新录用公务员林某,因试用期不合格被取消录用。下列说法正确的是:()A.
人们往往把35~50周岁的教师群体称为中年教师,他们一般从事教育工作超过十年,积
滴虫性阴道炎的治愈标准是A.连续3次月经后检查未找到滴虫 B.白带悬滴法检查滴
共用题干 张某与刘女士均为企业白领,2006年登记结婚。婚前两人约定每月各自从
已知两点A(4,0,5)和B(7,1,3),则下面与AB方向相同的单位向量e为(
2016年5月21日,位于甲国的A公司向位于乙国的B公司发出如下电文:“请于15
引进技术和进口设备其他费包括()A、外贸手续费 B、银行手续费 C、国外工程
最新回复
(
0
)