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、To Michigan. B、To China. C、To Maryland. D、To Canada. D 短文说,钻孔虫向北扩散至Ontario,Canada。故D是正确答案。
A、To Michigan. B、To China. C、To Maryland. D、To Canada. D 短文说,钻孔虫向北扩散至Ontario,Canada。故D是正确答案。
admin
2013-06-02
64
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.
The emerald ash borer has destroyed trees in the Midwest and as Far East in the United States as Maryland. 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. 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. 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. It examines and X-rays the seeds to make sure that 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.
选项
A、To Michigan.
B、To China.
C、To Maryland.
D、To Canada.
答案
D
解析
短文说,钻孔虫向北扩散至Ontario,Canada。故D是正确答案。
转载请注明原文地址:https://kaotiyun.com/show/Z8B7777K
0
大学英语六级
相关试题推荐
Musicproducesprofoundandlastingchangesinthebrain.Schoolsshouldaddmusicclasses,notcutthem.Nearly20yearsago,a
Musicproducesprofoundandlastingchangesinthebrain.Schoolsshouldaddmusicclasses,notcutthem.Nearly20yearsago,a
A、Theevidencefoundatthecrimescene.B、Thetestimonyofhistwofriends.C、Thejury’sprejudiceagainsthisrace.D、Thetwo
Gotapenhandy?Tobestestimateyourstart-upcosts,you’llneedtomakealistandthemoredetailedthebetter.Asmartway
ReturningtoScienceTeresaGarrettwasworkingpart-timeasabiochemistrypostdoc(博士后).Shehadaninfantathome,andsh
A、Hewastakingpicturesoncampusthen.B、Hisappearancewasunintentional.C、HeisamemberoftheschoolTVstation.D、Hewil
A、Theirparentscutbacktheloantothem.B、Thewomandoesn’twanttotakeanotherEnglishcourse.C、Theycan’taffordtherent
Lastyear,ournation’scapitalpassedthemurder-a-daymark,andthenumberofhomicidesisnowupsome50percentfromthatle
A、Lindamadeherownguitar.B、Lindataughtherselftoplaythepiano.C、Lindataughtherselftoplaytheguitar.D、Lindadoesn’
ArobotissolifelikethatitssweatsarehelpingtheUSArmytotestprotectiveclothing."Manny",asthedeveloperoftheman
随机试题
(2007年4月)(2006年5—4月)非法经营同类营业罪的犯罪主体是_______。
民族自治地方的区域界线变动的批准权属于()
某项资产在评估时,名义已使用年限为10年,根据该资产的技术指标每天应工作8小时,实际每天只工作7.2小时,由此可以估计该资产实际已使用年限为()
内因和外因对个体身心发展综合作用的汇合点是()。
下列费用中,不属于建设工程项目总投资中的设备工器具购置费的是( )。
资金来源也可统称为()。
下列合同的分类错误的是()
设,则a2=_____________.
阅读下列HTML文本和说明,在该HTML文本中存在5处错误,请指出错误所在的行号、错误原因以及改正的方法。[说明]这是一个简单的HTML文本,显示作者个人主页的登录界面。[HTML文本](1)<HTML>(2)<B
Wefindthatbrightchildrenarerarelyheldbackbymixed-abilityteaching.Onthecontrary,boththeirknowledgeandexperienc
最新回复
(
0
)