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
2018-07-27
23
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://jikaoti.com/ti/qvSFFFFM
0
大学英语六级
相关试题推荐
A、Theymadeenoughmoneytobuyanewhouse.B、Theyfoundlifeinthetreehouseinconvenient.C、Theygotsomecomplaintsfromt
A、Theyhavethesameviewonsomeotherpoints.B、TheyagreethatwatchingTVbenefitsus.C、Theyarearguingtooseriouslyabou
GeorgeHerbertMeadsaidthathumansaretalkedintohumanity.Hemeantthatwegainpersonalidentityaswecommunicatewithot
A、People’sreactionstoit.B、Theplotofit.C、Thecharactersinit.D、Thedirectorofit.A
RisingInequalityIsHoldingBacktheU.S.Economy[A]Inannouncinghisrunforthepresidencylastmonth,JebBushhassetan
RisingInequalityIsHoldingBacktheU.S.Economy[A]Inannouncinghisrunforthepresidencylastmonth,JebBushhassetan
Attentiontodetailissomethingeveryonecanandshoulddo—especiallyinatightjobmarket.BobCrossley,ahuman-resourceexp
A、AcitynamedMilton.B、AtownnamedMilton.C、TorontoAirport.D、MiltonAirport.B细节题。根据Ineedtogettoatowncalledum,Milt
Atsomepointin2008,someone,probablyineitherAsiaorAfrica,madethedecisiontomovefromthecountrysidetothecity.T
A、Totalkwithsomeoneorwithoneself.B、Tohavealongandgoodrelaxation.C、Todomoreaerobicexercises.D、Totakemoreant
随机试题
EndangeredSpeciesReading:PolarBearMakestheListInSpring2008,thepolarbearwasplacedontheendangeredspeciesli
下列各种社会意识中,属于非意识形态的是()。
50年代首先提出艺术接受中“再创造”“再评论”的理论是()
中小学德育工作最基本、最经常的途径是()
凝血因子活性测定所用的缓冲液为
牙隐裂好发于
决定合理用药水平的是
一新建双线铁路,设计行车时速160km,其中某段路基8.5km,设计填挖平衡,大部分填筑高度3~5m,挖方段坡度不大,山体除表层外,部分为中风化砂岩,部分弱风化,沿线两侧有少量村庄,无重要建筑物,最大挖深12m。填筑区有两段各长500m的软弱地基,软弱层
1805年,()在广州开设了广州保险公司,这是中国最早的一家保险公司
向阳电器公司销售部门对今年微波炉的销售量进行统计,发现今年前两个季度销售微波炉25万台,只是去年全国销售量的30%。向阳电器公司有关部门由此得出结论,今年微波炉的销售量肯定会低于去年。以下哪项如果为真,最能削弱上述结论?
最新回复
(
0
)