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
A、To Michigan. B、To China. C、To Maryland. D、To Canada. D
admin
2018-06-27
67
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、To Michigan.
B、To China.
C、To Maryland.
D、To Canada.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/rKT7777K
0
大学英语六级
相关试题推荐
A、Toprotectthemselvesorattractprey.B、Tomakethedeepseabrightandbeautiful.C、Tofindtheirwaysindarkness.D、Toatt
Forthispart,youareallowed30minutestowriteanessayonunderstandingothersbyreferringtoAbrahamLincoln’sremark,"I
A、Therearemoremalegeniusesthanfemalegeniuses.B、Peoplewithbetternutritionaremuchmoreintelligent.C、Femaleshavewe
Forthispart,youareallowed30minutestowriteashortessaybasedonthepicturebelow.Youshouldfocusontheimpactofs
A、Itprovedthatchocolatewasgoodforintelligence.B、ItassociatedtheconsumptionofchocolatewithNobelwins.C、Itnotedm
A、Theywillbuysomethingfromtheconveniencestores.B、Theywilltakeadvantageofthetimetorestawhile.C、Theywillhave
A、Asimplelifestyle.B、Amoreinterestinglifeorientation.C、Excitingoutdooractivities.D、Wildnessandattractionofthenat
A、Thefloorisslick.B、Thestaircaseissteep.C、Thepassageisnarrow.D、Thetreadisunsteady.B四个选项是四种描述,根据提示词floor、staircas
It’sperhapstheworld’smostfamousunderwaterattraction,immortalizedinfilmandinlegend:theTitanic.Butnowexpertssay
A、Ratherdifficulttoplease.B、Rudetowomendrivers.C、Talkativeandgenerouswithtips.D、Differentinpersonality.D①形容词选项,多
随机试题
对病人的适应性行为进行奖励的方法是
最常见的妄想类型是
【背景资料】某吹填工程,吹填区总面积2.5km3、吹填总容量2000万m3,分为A、B、C三个区进行吹填。A区吹填面积0.9km3、吹填容量750万m3;B区吹填面积0.75km2、吹填容量550万m3;C区吹填面积0.85km2、吹填容量700
传统折中理论认为,公司的加权平均资本成本先升后降,存在一个最优的资本结构。()
小玲性情沉静,情感发生缓慢而微弱,不外露,忍耐力强,她的气质类型属于()。
简述小学体育教学的一般性原则。
如果一个复选框被选中,则
计算斐波那契数列第n项的函数定义如下:intfib(intn){if.(n==0)return1;elseif(n==1)return2;elsereturnfib(n-1)+fib(n-2);}若执行函
在深度为5的满二叉树中,叶子结点的个数为()。
EversinceALGoreinventedit,theInternethasbeenaparadiseforthosewithacreativeattitudetofacts.Students,forexam
最新回复
(
0
)