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
52
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/3636509.html
相关试题推荐
[originaltext]Ateamofscientistsrecentlybeganaprojecttomeasurethe
[originaltext]Ateamofscientistsrecentlybeganaprojecttomeasurethe
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
[originaltext]Onewaythatscientistslearnaboutmanisbyanimals,sucha
[originaltext]Onewaythatscientistslearnaboutmanisbyanimals,sucha
[originaltext]Toooftenyoungpeoplegetthemselvesemployedquitebyaccid
随机试题
To:MarkHopkinsFrom:GeorgeWallaceSubject:March10InstallationDate:Ma
Itmightappeartoanycasualvisitorwhomayhavetakenafewridesaboutt
TheGreatDepressionspreadfromtheUStotherestofthecapitalistworld,
类似的观点目前还有市场。Viewpointslikethisstillhavesomeappealatpresent本句中的“还有市场”实际上是
项目目标的特点有()。A.多目标性 B.固定性 C.层次性 D.优先性
审计人员发现被审计的单位毛利率异常上升,可能存在的原因有()。A.产量提高
在我国的建设程序中,项目的设计、施工,直至项目交付使用称为()。A.项目动用(
某期货公司完全按照客户的交易指令入市交易,但因此产生了混码交易,交易中产生的损失
男,35岁,腹痛、反酸10年。1周来症状加重,并出现夜间痛,进食能部分缓解。
关于我国仲裁基本制度的说法,正确的是()。A.当事人对仲裁不服的,可以提起
最新回复
(
0
)