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
What have scientists discovered about plants and insects?
What have scientists discovered about plants and insects?
admin
2010-07-06
33
问题
What have scientists discovered about plants and insects?
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 use less 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 and 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
A、all insects will be eliminated
B、all insecticides will be abandoned
C、super-bugs resistant to all poisons come out
D、scientists must invent new insecticides
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/adDd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
Thestatement"Inmyfridgelessfiftieschildhood,Iwasfedwellandhealthily."suggeststhatWhatistheauthor’soverallat
Whyare"HowTo"booksingreatdemandintheUnitedStates?
Whatarethestudentsgoingtododuringthisclassperiod?
Whyare"Clovispeople"believedtofirstenterNorthAmerica?
Accordingtotheauthor,theconventionalnotionofintelligencemeasuredintermsofone’sabilitytoread,writeandcompute
Whydidtheintelligencetestbecomeunpopularinthepastfewdecades?
Whydidtheintelligencetestbecomeunpopularinthepastfewdecades?
Thedestructionofournaturalresourcesandcontaminationofourfoodsupplycontinuetooccur,largelybecauseoftheextreme
Whenwillshowersreachsouth-westEnglandandthesoutherncoastofWales?
随机试题
下列各项都被认为对技术风险的评价至关重要,除了()。
Underheavygunfire,theCNNcameramenrisktheirlivestogive______battlefieldreports.
与原发性肝癌的发生关系最密切的因素是
患者,男,28岁,出租车司机,感冒2日,发热头痛,拟服药治疗,执业药师建议,该患者不宜选用含马来酸氯苯那敏的成药是()。
单位银行结算账户按刚途分为()。
申请人符合会计从业资格考试报名基本条件且具备国家教育行政主管部门认可的中专以上(含中专)会计类专业学历(或学位)的,自毕业之日起()年内免试会计基础、初级会计电算化(或珠算五级)。
企业管理体制中的“制”指的是()。
下列关于月球的说法正确的是()。
TheRomanticPeriodinAmericanliteraryhistoryendedwiththepublicationof
Thereasonwhybirdsdon’tgetlostonlongflight______.Experimentsshowedthat______.
最新回复
(
0
)