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
Scientists have discovered that plants themselves produce many poisonous chemicals for (36)______ against insects. But insects h
Scientists have discovered that plants themselves produce many poisonous chemicals for (36)______ against insects. But insects h
admin
2009-04-23
32
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.
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
farmers should actually try to attract insects onto the crops they are trying to Protect
解析
转载请注明原文地址:https://kaotiyun.com/show/4ZZK777K
0
大学英语六级
相关试题推荐
Followingthe(success)______settlementofthestrike,thetrainserviceisnowbacktonormal.
Soloudly______thatpeoplecouldhearitoutinthestreet.
A—StockexchangeK—StocktransferB—BuyingandsellingstockL—StockcompanyC—StockmarketM—SharecapitalD—Currentprices
Havingworkedasapsychologistwithallkindsofpeople,I’velearnedthatsuccessfulpeoplearen’tnecessarilytheoneswithth
Itis(reason)______forparentstopayfortheirchildren’seducation.
A、Thetelephonenumber.B、Mr.Brown’saddress.C、MissSmith’smessage.D、Thetimeforthevisit.A题目询问的是,那位女士记录了什么。对话中男士问:“你记下了她
说明:假设你是LeekAir—conditioning公司售后服务部的JohnGreen,给客户写一封道歉信。时间:1月17日。内容:昨天收到客户的来信,信中称新买的空调没有按照规定的时间装好。向客户道歉,因为自己看错了时间而导致该错误的发生,并承
Goodevening,ladiesandgentlemen!Onbehalfofourcompany,I’dliketothankyouforcomingto【T1】______theopeningofourn
A、Takesomemedicine.B、Haveagoodrest.C、Betreatedinhospital.D、Takeaninjection.B对话中女士说:“大夫,我感觉身体不舒服。”男士回答:“好好休息一下,这样你就
Theauthorwasdisappointedtofindthat______.Whatdoestheauthorintendtosaybytheexampleinthesecondparagraph?
随机试题
下列功能与肺主治节无关的是()(2003年第4题)
我国成人教育管理体制的原则包括()
下列关于既往史的描述,正确的是()
左旋多巴治疗震颤麻痹的机制是
下列级数中条件收敛的是()。
心理咨询工作关注来访者是否有病(精神疾病),是为了()。
幼儿园课程目标主要分为总目标、年龄阶段目标、()、月或周目标、某一教育活动目标等五个层次。
函数fun的功能是:把形参a所指数组中的偶数按原顺序依次存放到a[0]、a[1]、a[2]、……中,把奇数从数组中删除,偶数个数通过函数值返回。例如:若a所指数组中的数据最初排列为:9、1、4、2、3、6、5、8、7,删除奇数后a所指数组中的数据
A、AtAnne’sClothingStore.B、Insideashoppingcenter.C、Atadowntownstreet.D、Inasuburbanresidentialdistrict.C男士问Anne’s
A、Itoffersabetterchancetohigh-levelstudents.B、Itdivideschildrenofffordifferentschools.C、Itselectsstudentsfort
最新回复
(
0
)