首页
登录
职称英语
[originaltext]A beetle invasion in the United States has killed at least twenty
[originaltext]A beetle invasion in the United States has killed at least twenty
游客
2024-04-04
61
管理
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 clear up the eggs of insects.
B、To help trees deliver water.
C、To look for the signs of insects.
D、To prepare for cutting down trees.
答案
C
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3539898.html
相关试题推荐
[originaltext]W:2millionhighschoolseniorsaregearingupthisfalltoappl
[originaltext]W:2millionhighschoolseniorsaregearingupthisfalltoappl
[originaltext]W:We’veallheardthesaying“Laughteristhebestmedicine.”Ho
[originaltext]Manisalandanimal,butheisalsocloselytiedtothesea.Thr
[originaltext]Manisalandanimal,butheisalsocloselytiedtothesea.Thr
[originaltext]Japanesestudentsworkveryhardbutmanyareunhappy.Theyfeel
[originaltext]Japanesestudentsworkveryhardbutmanyareunhappy.Theyfeel
[originaltext]Ilovetreesbecausetheyhavemanydifferentshadesofgreen,so
[originaltext]Ilovetreesbecausetheyhavemanydifferentshadesofgreen,so
[originaltext]Manycollegestudentshavegivenuptakingclassnotesbyhand.
随机试题
Initsvariousformsfromfictiontodocumentary,themotionpicturehasbecom
Somethinghasbeenhappeningtotheconceptof"fiction,"bothincriticald
InAmericanhighschoolstoday,it’stakenasagiventhatextracurricular(
驾驶汽车在山区道路转弯下陡坡路段遇对面来车应怎样行驶?()A.转弯前减速 B
对钢管混凝土柱中混凝土作用的描述,下列何项不正确?( )A.有利于钢管柱的稳定
治疗老年高血压的目标是血压降低至A.
全科医生与中医学如出一辙的是( )。A.强调医德和医患的关系 B.筛选疑难和
下列关于证券研究报告的销售服务要求的表述,不正确的是( ). Ⅰ.发布证券研
实载率可以综合反映车辆的()。A.行程利用程度 B.时间利用程度 C.工作车
选择额外支付劳动者1个月工资解除劳动合同的,其额外支付的工资应当按照()的标
最新回复
(
0
)