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
57
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:http://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
Innovation.It’swhatgotusthroughtheDarkAges.Butovertheyears,inst
B
王某,女性,45岁。尿频量多,混浊如脂膏,腰膝酸软,乏力,头晕耳鸣,口干唇燥,皮
A.黏液、脓血便B.稀糊状便C.米泔样便D.白陶土样便E.柏油样便消化道出血
医生根据病人的体温、血压、血液、心电图等检查资料,就能确诊病人的身体情况和病因,
李某是某有限合伙企业的普通合伙人,张某是该合伙企业的有限合伙人,二人在一次车祸
委托人销售自己使用过的固定资产,适用简易办法依照3%征收率减按2%征收增值税
下列关于项目组织再造的原则,说法正确的有()。A.尽可能保持项目工作的连
价值工程中的“价值”是指作为某种产品(或作业)所具有的功能与获得该功能的全部费用
现需对某行政大楼的设备及安装工程部分编制设计概算,其合适的方法有()。A、概算
最新回复
(
0
)