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
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.
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、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
短文说,钻孔虫是在树上产卵,孵出的幼虫钻到内层树皮吸取营养,故把部分树皮削去会使树更容易成为攻击的目标,当钻孔虫来袭时就能有所发觉。故C是正确答案。从选项可以初步猜测题目与树木和昆虫有关。解题时需听清楚问题问的是什么。
转载请注明原文地址:http://tihaiku.com/zcyy/2939113.html
相关试题推荐
[originaltext]W:Doyouwantmetoexplainthesequestionsbeforetheexam?M:
[originaltext]W:Doyouwantmetoexplainthesequestionsbeforetheexam?M:
[originaltext]W:Doyouwantmetoexplainthesequestionsbeforetheexam?M:
[originaltext]Inthepastindustrieshadmorefreedomthantheyhavenow,a
[originaltext]Inthepastindustrieshadmorefreedomthantheyhavenow,a
[originaltext]Inthepastindustrieshadmorefreedomthantheyhavenow,a
[originaltext]LastsummerIwentthroughatrainingprogramandbecameali
[originaltext]LastsummerIwentthroughatrainingprogramandbecameali
[originaltext]W:Interestedinthisbook?Thisisourbestsellerthisweek.M:
[originaltext]W:Interestedinthisbook?Thisisourbestsellerthisweek.M:
随机试题
Aninvisibleborderdividesthose,arguingforcomputersintheclassroomon
[originaltext]M:Hi.Ihaveareservationfortonight.MynameisCharlesNelso
图示梁的正确挠曲线大致形状是( )。 A.图(A) B.图(B) C.图
Lb1A5381图A-3是220kV线路零序参数的测试接线。表A-1中为测试
某公司是一家新建企业,为了打好管理基础,保证产品质量,公司决定从全员质量教育工
下列说法中,正确的是( )。A.大赦既赦其刑,又赦其罪B.特赦只赦其刑
中国银行业监管应当遵循的基本原则包括()。 A.公正原则B.公开原则C
自我概念的功能主要包括()。A.保持个体内在的一致性 B.解释经验 C.控制
甲公司系增值税一般纳税人,2019年5月1日甲公司对某生产线进行改良,
经济效果评价方法的分类中,对定量分析,按其是否考虑时间因素可以分为()。A.静态
最新回复
(
0
)