首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A、Using less insecticide. B、Giving the plants up. C、Spraying crops frequently. D、Trying other insecticide. A短文提到了科学家给农场主的三点建议:少用
A、Using less insecticide. B、Giving the plants up. C、Spraying crops frequently. D、Trying other insecticide. A短文提到了科学家给农场主的三点建议:少用
admin
2016-08-25
35
问题
Scientists have observed 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—insecticide. This is why resistance of insects to insecticide has developed so rapidly. What should be done? Scientists studying the problem suggest that farmers use less insecticide. 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 insecticide at once. To survive, the insects would need to become resistant to two or more poisons 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.
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 our poisons invade our farms and devour our crops.
19 What does the speaker say about plants?
20 What is mentioned as one of the suggestions raised by scientists?
21 What is the most surprising suggestion scientists give?
选项
A、Using less insecticide.
B、Giving the plants up.
C、Spraying crops frequently.
D、Trying other insecticide.
答案
A
解析
短文提到了科学家给农场主的三点建议:少用杀虫剂、同时使用两种或三种杀虫剂、吸引别的昆虫到田间。A正是短文中提及的建议之一,故为答案。
转载请注明原文地址:https://kaotiyun.com/show/ZQY7777K
0
大学英语四级
相关试题推荐
PreparingforComputerDisastersSummaryA)Whenhomeofficecomputersgodown,manysmallbusinessesgrindtoahalt.Fortunatel
ShoppersonBlackFriday,thetraditionalstartoftheholidayshoppingseasoninAmerica,arenotoriouslyaggressive.Someeven
ResearcherssayextravitaminEfedtoturkeysappearstohelpcontrolinfectionsfromlisteria(李氏杆菌).Peoplewhoeatfoodsthat
Housingofficialssaythatlatelytheyarenoticingsomethingdifferent:studentsseemtolackthewill,andskill,toaddresst
PresidentBushandthe9/11Attacks2000ElectionA)AsClinton’spresidencycametoaclose,Democra
Writeashortessaybasedonthepicturebelow.YoushouldstartyouressaywithabriefaccountofYoungstersshouldbeAwayfr
A、Theyshouldgiveuptalking.B、Theyshouldbothmakeacompromise.C、Theycanmeetnexttime.D、Theyarebothhalfway.B男士话中的“
A、Theywillbecomeinactiveanddull.B、Theywillnotgotocinemasasoften.C、Theywillforgettodotheirhomework.D、Theywi
Writeashortessaybasedonthepicturebelow.Youshouldstartyouressaywithabriefaccountofpicture,thenexpressyourv
A、Themanisfondoftraveling.B、Thewomanisaphotographer.C、Thewomantookalotofpicturesatthecontest.D、Themanadmi
随机试题
画像石是兼具()与雕刻两种形式的艺术。
在人类生态学上,疾病与健康有关的三大因素是下列中的哪一项
解热镇痛药只能解除钝痛,对剧痛无效。()
介导Ⅳ型超敏反应的免疫细胞是()。
只有在()时,财政赤字才会扩大国内需求。
增值税发票的发票联为销售方核算销售收入和增值税销项税额的记账凭证。()
除法律另有规定外,下列财产中,不得用于抵押的有()。
有效的紧急事件处理程序应该包括哪几个过程?
在讲解“相向而行的行程问题”时,教师在幻灯片上面一条线段表示两地间的距离,并出示两个小人,通过幻灯机显示在屏幕上.教师的这种教学方法属于().
8086/8088微处理器由两个彼此独立又互相配合的部件组成,它们分别称为总线接口部件和( )。
最新回复
(
0
)