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、Shipments of goods from China. B、Detection trees. C、The seeds from ash trees. D、The invasion of the emerald ash borer. D
A、Shipments of goods from China. B、Detection trees. C、The seeds from ash trees. D、The invasion of the emerald ash borer. D
admin
2019-03-17
95
问题
A beetle invasion in the United States has killed at least twenty million ash trees. The invasion of the emerald ash borer was first discovered near Detroit, Michigan, in 2002. Experts believe the small green insects arrived in the 1990’s in shipments of goods from China.
[16] The emerald ash borer has destroyed trees in the Midwest and as far East in the United States as Maryland. [17] The insects have also spread as far north as Ontario, Canada.
Ash trees can resist many diseases. But they cannot resist the emerald ash borer. [18-1] It lays eggs on the bark.The young larva drill into and feed on the inner bark. This harms the ability of the tree to transport water and nutrition.
In some places, farmers are using “detection trees”. They have an area where bark has been cut away. The area circles the tree. [18-2] The process weakens the tree. It makes them easier targets for borers, and shows if the insects are nearby.
Efforts to stop the spread of the emerald ash borer include cutting down affected trees. There are worries that the ash tree might disappear unless the invasion is controlled. To prepare for such a possibility, a government laboratory is asking people to send in the seeds from ash trees. [19] It examines and X-rays the seeds to make sure there are no living borer fertilized eggs.Only the best seeds are remained and then sent for storage in a seed bank. There, they are dried and frozen. Should the seeds ever be needed, the hope is that scientists might someday develop an ash tree that could resist the little green attackers.
1.What’s the speaker mainly talking about?
2.How far do the insects spread northward?
3.Why is part of the bark cut away?
4.What is the government laboratory trying to do?
选项
A、Shipments of goods from China.
B、Detection trees.
C、The seeds from ash trees.
D、The invasion of the emerald ash borer.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/5pH7777K
0
大学英语六级
相关试题推荐
计划生育(familyplanning)是中国的一项基本国策。20世纪70年代末,为了控制人口过度增长,中国政府开始推行计划生育,提倡一对夫妇只生一个孩子。这项政策有效缓解了人口对资源、环境的压力。21世纪初,中国政府对计划生育政策做出了一些调整,允许双
Anewalcoholdetectionsystemcouldbeintroducedincarsby2020,preventingintoxicated(喝醉的)driversfromstartingtheircars.
A、Whetherthewateriscleanenough.B、Ifitcanbeusedinvariousweatherconditions.C、Ifitwillleadtolessvisitors.D、Wh
A、EverytimetheywatchTV.B、Whentheymakemistakes.C、Whenthey’regoingonholiday.D、Whentheymeetforecasters.C原文提及“观众只在
Postgraduatedilemmas[A]Decidingwhetherornottobecomeapostgraduatecanbeadaunting(令人畏缩的)prospect.Evenifyouares
A、Tosatisfyhisrequirements.B、Toshowhowthesoftwareworks.C、Toaskhimtobuyotherproducts.D、Tolethimcompareprices
Waterscootersarewatervehiclesthatlookverymuchlikemotorcycles.Nowadaysspeedycolorfulwaterscootersare【B1】______pop
WilmaSubrahadnointentionofbecomingapublicspeaker.After【B1】______fromcollegewithdegreesinchemistryandmicrobiolog
Employersarefarlesslikelytoemploypeoplewithmentalillnessesthanthosewithphysicalailments(疾病),areportshows.The
Mathematicalabilityandmusicalabilitymaynotseemonthesurfacetobeconnected,butpeoplewhohaveresearchedthesubject
随机试题
下列选项中,属于诺成合同的是()
某设备安装工程直接费为180万元,间接费为27万元,利润为10万元,营业税率为3%,则该工程的营业税为( )万元。
某堤防工程,发包人与承包人依据《水利水电工程标准施工招标文件》(2009年版)签订了施工承包合同,合同中的项目包括土方填筑和砌石护坡,其中土方填筑200万m3,单价为10元/m3;砌石10万m3(不考虑砌石定额系数,所需开采石方10万m3),单价为40元/
按业务范围,导游人员可分为()
中国人民艰苦卓绝的革命斗争中,诞生了不少脍炙人口的歌曲。下列歌词均来自这些著名歌曲,其中创作时期与其他三首不同的是()。
2019年9月29日上午,《山西省红色文化遗址保护利用条例》(以下简称《条例》)新闻发布会在省人大常委会会议厅召开。该《条例》于2019年()开始施行。
近日,环保局要到你社区宣传推广垃圾处理分类的方法。你是社区工作人员,领导让你组织居民去参加,请问你如何开展本次活动?
∪∩∈~⊙∩≌~
在不同AS之间使用的路由协议是()。
通货膨胀
最新回复
(
0
)