首页
登录
职称英语
[originaltext] (32)Scientists have discovered that plants themselves produce
[originaltext] (32)Scientists have discovered that plants themselves produce
游客
2023-09-09
57
管理
问题
(32)Scientists have discovered that plants themselves produce many poisonous chemicals for defense against insects. But insects have developed ways of dealing with them. Guess how many years have the insects been eating plants. The number itself will scare you. (33) In fact, insects have been eating plants for as many as 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 (34) that farmers use less insecticides. At the moment, farmers (34)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, (34)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 new insects onto the crops they are trying to protect. The new insects will mate with those which survived from a certain kind of insecticide and will lessen the latter’s resistance to it.
(35) Scientists 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
A、Because farmers use less insecticides now.
B、Because farmers have been using insecticides for many years.
C、Because insects use the mechanisms against plants to fight insecticides.
D、Because insects have been eating plants for many million years.
答案
D
解析
昆虫吃植物的历史已经长达两亿五千万年“In fact, insects have been eating plants for as many as 250 million years”,所以它们的抗杀虫剂性能增长得非常迅速。因为它们已经习惯不断进化,对抗各种植物杀虫剂、人工杀虫剂:Now insects are using these same mechanisms to deal with man-made poisons—insecticides...insecticides has develop
转载请注明原文地址:https://tihaiku.com/zcyy/2999548.html
相关试题推荐
[originaltext]Theexistenceofblackholehadlongbeenpredictedbytheory
[originaltext]Theexistenceofblackholehadlongbeenpredictedbytheory
[originaltext]W:Bob,Haveyouseenanymoviesrecently?M:Yes,I’veseenafe
[originaltext]W:Bob,Haveyouseenanymoviesrecently?M:Yes,I’veseenafe
[originaltext]W:Mike,anyplansforthesummervacation?M:Iwanttotravel,
[originaltext]M:Now,whatseemstobethetrouble,Mrs.Stephens?W:I’vebeen
[originaltext]M:Now,whatseemstobethetrouble,Mrs.Stephens?W:I’vebeen
[originaltext]M:Now,whatseemstobethetrouble,Mrs.Stephens?W:I’vebeen
[originaltext]M:Now,whatseemstobethetrouble,Mrs.Stephens?W:I’vebeen
[originaltext]M:Now,whatseemstobethetrouble,Mrs.Stephens?W:I’vebeen
随机试题
Likefinefood,goodwritingissomethingweapproachwith【B1】______andenjo
Eachartistknowsinhisheartthatheissayingsomethingtothepublic.He
WhatjobpositionisofferedtoMr.Smithintheletter?[br]HowcanMr.Smith
初步设计工作的输入内容包括()。A.项目设计范围和设计分工 B.经双方批准
命名下列化合物:(1)CH3COCH3__________;(2)CH3O
公路本质安全包括明确性、主动性,宽容性和冗余性这四种基本安全要素。
下列各项中,不符合内部牵制的要求的是()。A、出纳人员管票据 B、出纳人员
依据《企业所得税法》的规定,下列有关计算应纳税所得额时扣除的部分的说法错误的是:
下列哪项是模块级初始化的内容()。A、设置操作员 B、设置系统控制参数 C、
男性,20岁,学生。因咳嗽伴右胸不适20天,低热伴乏力、盗汗6天来诊。体检发现右
最新回复
(
0
)