首页
登录
职称英语
[originaltext] A beetle invasion in the United States has killed at least tw
[originaltext] A beetle invasion in the United States has killed at least tw
游客
2023-08-19
17
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.
The emerald ash borer has destroyed trees in the Midwest and as Far East in the United States as Maryland. 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://tihaiku.com/zcyy/2939114.html
相关试题推荐
[originaltext]AmericanvisitorstoEasternAsiaareoftensurprisedandpuz
[originaltext]AmericanvisitorstoEasternAsiaareoftensurprisedandpuz
[originaltext]InBritainthebiggestnumberofworkingforeignerscomesfro
[originaltext]M:I’msotired,Ican’tseestraight.W:You’vebeentiredalot
[originaltext]W:Haveyouevervisitedaredwoodforest?Irecentlyhadachanc
[originaltext]W:Haveyouevervisitedaredwoodforest?Irecentlyhadachanc
[originaltext]W:Haveyouevervisitedaredwoodforest?Irecentlyhadachanc
[originaltext]M:I’mlookingforanunfurnishedtwo-bedroomapartment,butall
[originaltext]M:I’mlookingforanunfurnishedtwo-bedroomapartment,butall
[originaltext]M:I’mlookingforanunfurnishedtwo-bedroomapartment,butall
随机试题
Friendshipisoneofthegreatestpleasurethatpeoplecan(11).Atruefr
[originaltext]Thunderstormsaretheleastdangerousandleastviolentofal
函数 的可去间断点的个数为( )。A.1 B.2 C.3
植物细胞分化的第一步是()A.细胞分裂 B.合成DNA.C.合成CTK D
任何两个计量经济模型的都是可以比较的。()
A.2份5%葡萄糖,1份生理盐水 B.2份生理盐水,1份1.4%NaHCO
394.党支部应按照规定,向()通报党的工作情况,公开党内有关事务。 A.党
在贷款决策中,商业银行需要使用的财务指标主要包括()。A.销售利润率 B.净
气滞血瘀型痛经首选A.少腹逐瘀汤 B.膈下逐瘀汤 C.血府逐瘀汤 D.金匮
关于核设施的环境影响评价书的审批,以下说法正确的是( )。A.核设施选址的环境
最新回复
(
0
)