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
专升本
A truly extraordinary variety of alternatives to the chemical control of insects is available. Some are already in use and h
A truly extraordinary variety of alternatives to the chemical control of insects is available. Some are already in use and h
admin
2015-10-30
47
问题
A truly extraordinary variety of alternatives to the chemical control of insects is available.
Some are already in use and have achieved brilliant success. Others are in the stage of laboratory testing. Still others are little more than ideas in the minds of scientists, waiting for the opportunity to put them to the test. All have this in common; they are biological solutions, based on understanding of the living organisms they seek to control, and of the whole structure of life to which these organisms belong. Specialists representing various areas of the vast field of biology are contributing, all pouring their knowledge and their creative inspirations into the formation of a new science of biological control. A century ago with the first attempts to introduce natural enemies of insects that were proving troublesome to farmers, the efforts sometimes moved slowly or not at all, but now and again gathered speed and momentum under the impetus of an outstanding success. Some of the most fascinating of the new methods are those that seek to turn the strength of a species against itself—to use the drive of an insect’ s life forces to destroy it. The most spectacular of these approaches is the "male sterilization" technique developed by the chief of the U. S. Department of Agriculture’ s Entomology Research Branch, Dr. Knipling and his associates.
About a quarter of a century ago Dr. Knipling startled his colleagues by proposing a unique method of insect control. If it were possible to sterilize(使绝育)and release large numbers of insects, he theorized, the sterilized males would, under certain conditions, compete with the normal wild males so successfully that, after repeated releases, only infertile(不生育的)eggs would be produced and the population would die out.
"Alternatives to the chemical control"(Line 1)means______.
选项
A、other kinds of chemical control of insects
B、altered methods of the chemical control of insects
C、ways other than the chemical to control insects
D、choices of chemicals to control insects
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/UtYC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
Onetypeofpersonthatiscommoninmanycountriesistheonewhoalwaystriestodoaslittleaspossibleandtogetasmuch【5
Onetypeofpersonthatiscommoninmanycountriesistheonewhoalwaystriestodoaslittleaspossibleandtogetasmuch【5
Onetypeofpersonthatiscommoninmanycountriesistheonewhoalwaystriestodoaslittleaspossibleandtogetasmuch【5
Somepeoplehateeverythingthatismodern.Theycannotimaginehowanyonecanreallylikemodernmusic;theyfindithardtoac
Pickouttheappropriateexpressionsfromtheeightchoicesbelowandcompletethefollowingdialoguesbyblackeningthecorresp
Pickouttheappropriateexpressionsfromtheeightchoicesbelowandcompletethefollowingdialoguesbyblackeningthecorresp
Thereareadvantagesanddisadvantagesto【21】AsianandWesterneducationalmethod.Forexample,oneadvantage【22】theeducationi
Thereareadvantagesanddisadvantagesto【21】AsianandWesterneducationalmethod.Forexample,oneadvantage【22】theeducationi
Woodsmen,huntersandtrackerslearnedtofollowandreadthe【21】left,behind【22】animals,men,natureandtime.Theirabilityto
Theangrywomansatinthestationoffice."Therailwayshouldpayme$12."ShesaidtoHarry,themanwho【21】theticket."Myti
随机试题
审美意象是用来表达某种抽象的观念或者哲理的艺术形象,它是艺术家在构思过程中,将自己的审美情感、审美认识与客观的事物相融合,并以一定的艺术表达方式呈现出来的内心视像。根据上述定义,下列不属于审美意象的是:
下列哪些药是抗痛风药
A.治疗指数B.效能C.效价强度D.半数有效量E.亲和力表示药物安全性的指标是()
(2002年考试真题)有限责任公司的下列事项中,根据《公司法》规定,必须经代表2/3以上表决的股东通过才能作出决议的有()。
某位家长带3岁小孩前来咨询,患儿常有多汗、易惊、出牙迟及枕秃等症状。前胸部两侧肋骨与软骨交界处外凸成“肋骨串珠”,肋下缘外翻,胸部前凸成鸡胸,脊柱后凸成驼背,腹肌软弱无力,腹胀。请根据以上情形回答问题:建议补充的含相关营养素丰富的动物性食物、植物性食
秦始皇时期,某地有甲乙两家相邻而居,但积怨甚深。有一天,该地发生了一起抢劫杀人案件,乙遂向官府告发系甲所为。甲遭逮捕并被定为死罪。不久案犯被捕获,始知甲无辜系被乙诬告。依据秦律,诬告者乙应获下列哪种刑罚?()
用二分法进行插入排序,记录移动个数为
下列描述中错误的是
A、HissuccessfulreleasefromarrestinMiami.B、Hisambitiontobecomesuccessfulincareer.C、Thepursuitofgreatfortunein
Healways______(每天留出时间)totellsmilestohischildren.
最新回复
(
0
)