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
74
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
Thefirstwaywecanapproachlanguageisasaphenomenonoftheindividual
Thehousewillbecold.Makesure____________(你开了暖气设备).Thehousewillbecold.Ma
Memorizationwhichdoesnotincludethinkingandunderstanding_____studentsbein
降低平均资金成本的途径有()。A.降低各项资金的贷款比重 B.降低各项资金
下列哪项不属于头皮血肿范畴()A.帽状腱膜下血肿 B.骨膜下血肿 C.
【教学过程】 (一)创设情境,导入新课 引导学生说出学过或知道的描写冬天景色的古诗词句;如:柳宗元的《江雪》《风雪宿芙蓉山主人》、岑参的《白雪歌送武判官
口是衡量资产相对风险的一项指标。B大于l的资产,通常其风险小于整体市场组合的风险
有益于他人,需要或接受报酬的行为属于()。 (A)利他行为(B)助人行为
周某在某企业工作已满8个月,此时企业违反规定解除了劳动合同。根据《劳动合同法》,
预制构件进场时应对其主要受力钢筋数量、规格、间距、保护层厚度及混凝土强度等进行实
最新回复
(
0
)