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
2024-04-15
37
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. [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://tihaiku.com/zcyy/3556151.html
相关试题推荐
[originaltext]Everyyear,peopleinAmericauseenergyequaltoover30mil
[originaltext]Everyyear,peopleinAmericauseenergyequaltoover30mil
[originaltext]Everyyear,peopleinAmericauseenergyequaltoover30mil
[originaltext]Ifsheernumbersprovideanyproof,America’suniversitiesar
[originaltext]Youprobablyknowwhatamobileis,butthemobileI’mtalkin
[originaltext]Youprobablyknowwhatamobileis,butthemobileI’mtalkin
[originaltext]W:Iwonderifyoucouldtellmealittlebitaboutyourjobasa
[originaltext]W:Iwonderifyoucouldtellmealittlebitaboutyourjobasa
[originaltext]W:Iwonderifyoucouldtellmealittlebitaboutyourjobasa
[originaltext]W:Charles,asasinger,doyouevermakeyourselfcrywhenyous
随机试题
Afullmoonwasshiningdownonthejungle.AccompaniedonlybyanIndiangui
Wecouldnotobtainanyexactinformation______whereshewas.A、farfromB、ast
Friendshipisoneofthebasicbondsbetweenhumanbeings.Whilethecharact
AfederaljudgeinCaliforniahasdismissedalawsuitagainsttheCoca-Co
Theretiredmanlookedwonderfully(health)______.healthylook是系动词,后用形容词作表语,副词wo
患者右上腹疼痛约10天,厌油腻,超声检查见胆囊内强回声团,可移动,如超声图所示,
学龄儿童复种卡介苗前,应做的特异试验是A.OT试验 B.卡介苗试验 C.链霉
人在每一瞬间,将心理活动选择了某些对象而忽略了另一些对象。这一特点指的是注意的(
(2016年真题)南沙参除清肺养阴外,又能( )A.退热除蒸 B.凉血止血
应用高剂量β?受体激动剂可引起何种严重的症状,从而导致心律不齐A.低镁血症 B
最新回复
(
0
)