首页
登录
职称英语
[originaltext]A beetle invasion in the United States has killed at least twenty
[originaltext]A beetle invasion in the United States has killed at least twenty
游客
2023-08-10
31
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.
[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、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
转载请注明原文地址:https://tihaiku.com/zcyy/2914774.html
相关试题推荐
[originaltext]InAmerica,driver’seducationispartoftheregularhighsc
[originaltext]InAmerica,driver’seducationispartoftheregularhighsc
[originaltext]InAmerica,driver’seducationispartoftheregularhighsc
[originaltext]AnewenemyisthreateningJapanesetraditions:leisure.Asp
[originaltext]AnewenemyisthreateningJapanesetraditions:leisure.Asp
[originaltext]AnewenemyisthreateningJapanesetraditions:leisure.Asp
[originaltext]Thepodcastrevolutioniseruptingallovertheworld—andsee
[originaltext]Thepodcastrevolutioniseruptingallovertheworld—andsee
[originaltext]Thepodcastrevolutioniseruptingallovertheworld—andsee
[originaltext]ThenumberofspeakersofEnglishinShakespeare’stimeises
随机试题
Somesayitisevidentthatcomputerscandamageaperson’seyesight.Since
TopicMyViewonOuterSpaceExplorationForthispart,youareallowed30
Someoneorsomethingthatis______looksstrongandisunlikelytobeeasilyda
5个64kb/s的信道按统计时分多路复用在一条主线路上传输,主线路的开销为
下述哪一项不是噬血细胞综合征的表现A.血清间接胆红素升高 B.血甘油三酯升高
Whatpurposedopost-listeningactivities
外资股国际推介与询价包括()。A:预路演 B:路演推介 C:簿记竞价 D:
预防性树脂充填,错误的操作方法是A.去净龋坏组织,并做适当预防性扩展 B.酸蚀
(2021年9月贵州真题)点支承玻璃幕墙的玻璃肋比必须采用()A.夹层玻璃 B
A.甘露醇 B.支链氨基酸 C.糖皮质激素 D.左旋多巴 E.乳果糖治疗
最新回复
(
0
)