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
39
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
About700,000childreninMexicodroppedoutofschoollastyearasrecession-strickenfamiliespushedkidstowork,andaweak
Gotapenhandy?Tobestestimateyourstart-upcosts,you’llneedtomakealistandthemoredetailedthebetter.Asmartway
Hotelseagertosatisfythegrowingdesireofbusinesstravelersforeco-friendlylodgingarefindingthattheirenvironmentala
TheCaseAgainstRetirementAh,retirement!Beforethe1950s,itwassomethingonlythewealthycouldaffordtodo.Everyone
TheCaseAgainstRetirementAh,retirement!Beforethe1950s,itwassomethingonlythewealthycouldaffordtodo.Everyone
They’rethesortofscoresthatdrivehigh-schoolhistoryteacherstodrink.WhenNewsweekrecentlyasked1000UScitizenstot
Hegaveapledge______(以友好的方式来处理这些事务).
A、Theweekendhasdecreasedinlength.B、Thenumberofnationalholidayshasincreased.C、Peopleworkfewerdaysperweek.D、Peo
BillGatesbelievesthattheAmericanhighschoolsare"obsolete"in______.Inordertocompetewithoverseasstudents,America
ArobotissolifelikethatitssweatsarehelpingtheUSArmytotestprotectiveclothing."Manny",asthedeveloperoftheman
随机试题
社会工作者小李接待了前来求助的王女士母子。王女士告诉小李,儿子沉迷网络游戏不爱学习、父母劝他也不听,还与父母顶撞,王女士希望社会工作者小李能帮助她教育小强。小李在确认小强有接受服务的意愿后,与王女士母子签订了服务协议。小李的上述做法属于社会工作通用过程中的
脓尿蛋白定性常为阴性。()
患者,女,10岁半,左下颌第一乳磨牙远中邻殆面充填物完好,松(Ⅱ度),且牙冠透粉红色。最可能的诊断是
水利工程质量事故分为()。
管片的衬砌拼装方式分为()。
下列选项中,应征收资源税的是()。
与成就动机关系最密切的是个体的()。
【2015河北沧州】()是教师最神圣的权利。
以下不属于沟通管理范畴的是(54)。
QuantityA:abQuantityB:0
最新回复
(
0
)