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、Collect ash tree seeds for experiment. B、Preserve the healthy ash tree seeds. C、Set up a new seed bank for research. D、Develop
A、Collect ash tree seeds for experiment. B、Preserve the healthy ash tree seeds. C、Set up a new seed bank for research. D、Develop
admin
2016-04-02
31
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. [19]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. [21]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.
19. How far do the insects spread northward?
20. Why is part of the bark cut away?
21. What is the government laboratory trying to do?
选项
A、Collect ash tree seeds for experiment.
B、Preserve the healthy ash tree seeds.
C、Set up a new seed bank for research.
D、Develop a new breed of ash tree.
答案
B
解析
短文说,实验室对种子进行检查和照x-ray,确保没有钻孔虫的受精卵,只有最好的才被保存起来。故答案是B。从选项可以初步猜测题目与措施有关。“Only”表明文章要提出特殊的要点了,要提高警惕。
转载请注明原文地址:https://jikaoti.com/ti/ZuJFFFFM
0
大学英语六级
相关试题推荐
Exceptionalchildrenaredifferentinsomesignificantwayfromothersofthesameage.Forthesechildrentodeveloptotheirf
Manycountrieshaveaholidaytocelebrateworkers’rightsonoraroundMay1,butLabourDayinCanadaiscelebratedonthefir
Manycountrieshaveaholidaytocelebrateworkers’rightsonoraroundMay1,butLabourDayinCanadaiscelebratedonthefir
A、Anattorney.B、Ahealthcareconsultant.C、Atownplanner.D、Abeautician.A由男士提到的I’malawyer可知,男士是个律师,故答案为A)。
A、DevelopmentoftheNationalFlagB、PoweroftheNationalFlagC、TypesofFlagsD、UsesofFlagsA短文主要介绍了国旗在古代的发展,故答案为A)。
A、Sheshouldtakesomemedicineandmorewater.B、Sheshouldtakecareofherrestanddrinkmorewater.C、Sheshouldgiveuphe
A、Walkingthedog.B、Cuttingthegrass.C、Takingcareofthechildren.D、Feedingthefish.C细节题。Marsha照看房子的时候要修剪草坪,给植物浇水,Eric托管房
It’sperhapstheworld’smostfamousunderwaterattraction,immortalizedinfilmandinlegend:theTitanic.Butnowexpertssay
随机试题
当事人逾期不履行行政处罚决定的,作出行政处罚决定的行政机关可以采取的措施包括()。
Thereisameasurablerelationbetweenhowmuchapersonlearnsandhisattitudetowardthesubjecttobelearned.Whenfacedwi
呼吸性酸中毒合并代谢性碱中毒与下列哪些因素有关
风疹的皮疹特点是
FIDIC施工合同条件规定的合同有效期的结束时间是以( )日为标志。
存款准备金政策是中央银行实施货币政策的重要工具,其主要内容包括()。Ⅰ.规定存款准备金计提的基础Ⅱ.规定法定存款准备金率Ⅲ.规定存款准备金的构成Ⅳ.规定存款准备金的上限Ⅴ.规定存款准备金提取的时间
自2008年1月1日起开始施行的
诉讼时效作为权利人不行使权利就丧失请求人民法院依胜诉程序强制义务人履行义务的期间,一般适用于()
考生文件夹下存在一个数据库文件“samp2.accdb”,里面已经设计好“tTeacher1”和“tTeacher2”两个表对象及一个宏对象“mTest”。试按以下要求完成设计:(1)创建一个查询,查找并显示教师的“编号”、“姓名”、“性别”、“
Philosophicalproblemsarisewhenpeopleaskquestionsthat,thoughvery____,havecertaincharacteristicsincommon.
最新回复
(
0
)