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
2023-08-12
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、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://tihaiku.com/zcyy/2920692.html
相关试题推荐
中国姓氏是血缘关系的符号,其历史可追溯到原始社会时期。在战国(thewarringStates)以前,只有皇室和贵族才有姓,战国以后,平民才有了姓氏
重阳节(theDoubleNinthFestival),在每年的农历九月初九,是中国的传统节日。早在战国时期(theWarringStates
风水(Fengshui)是中国历史悠久的一门玄术(magicart),起源于战国时代(theWarringStatesPeriod)。风水的核心
[originaltext]W:Whenwasthelasttimeyouwentforawalkinyourlocalpark?
[originaltext]W:Whenwasthelasttimeyouwentforawalkinyourlocalpark?
[originaltext]W:HelloLadiesandGentlemen,itisagreatpleasuretohaveSco
[originaltext]E-booksarebringingaboutaprofoundrevolutioninthewayb
[originaltext]AmericanmagicianDavidBlaineistobesuspendedinaglass
[originaltext]AmericanmagicianDavidBlaineistobesuspendedinaglass
[originaltext]AmericanmagicianDavidBlaineistobesuspendedinaglass
随机试题
ThepartybeganshortlyafterMr.Wood,wholivedintheflatbelow,signedt
Ifyouhaveeverwonderedjusthowharditisforkidsfrombrokenneighborh
Itisnaturaltofeeluncomfortableinalanguageclass.You’reusedtobein
[originaltext]M:Howisthemovielastnight?W:TheworsttendollarsI’veeve
患儿,女孩,7岁,全身水肿、尿少4天入院,体查:神清,双眼睑水肿明显,双下肢非凹
体育教学研究中,选择两个自然班分别作为实验组和对照组进行实验,实验前后进行对比测
教师或学校不得以各种理由随意对学生进行搜查,不得对学生关禁闭,因为学生有( )
属于低分子量肝素抗凝机制特点的是A:对FⅩa的抑制活性相对增强B:对FⅩa的抑
保险代理人向( )收取代理手续费。A.保险人 B.投保人和保险公司 C.被
桥墩流水施工的桥墩数量太多时,将多个桥墩的相同工序合并为一个工作,简化为相同桥墩
最新回复
(
0
)