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、To Michigan. B、To China. C、To Maryland. D、To Canada. D
A、To Michigan. B、To China. C、To Maryland. D、To Canada. D
admin
2018-07-27
45
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、To Michigan.
B、To China.
C、To Maryland.
D、To Canada.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/1EH7777K
0
大学英语六级
相关试题推荐
TheFightAgainstSmogForthispart,youareallowed30minutestowriteanessaycommentingontheremark"Sincelastyearthe
A、Itmayexcludesomepeoplewithotherpreference.B、Itisbetternottoforcethemontoothers.C、Itisacceptableonlyamong
A、Theman’spersonalexperienceinmilitaryservice.B、Theman’stravelexperienceinAsiabytrain.C、Theman’stravelexperien
A、Polishingtheirapplicationforms.B、Broadeningtheiroptionsofcolleges.C、Benefitingfromalow-costschool.D、Workinghard
A、Itisapopulartouristdestination.B、Thetrafficisveryconvenientthere.C、Therentisquitecheapthere.D、Itisaquiet
Adultsaregettingsmarteraboutbowsmartbabiesare.Notlongago,researcherslearnedthat4-day-oldscouldunderstand【B1】__
Adultsaregettingsmarteraboutbowsmartbabiesare.Notlongago,researcherslearnedthat4-day-oldscouldunderstand【B1】__
Marketplaceorpeer-to-peer(P2P)lendingmatchesborrowersandlendersonlow-costonlineplatforms.Byskirtingbanks,P2Plendi
GetEnoughSleep—orElse!Agoodnight’ssleepismoreimportanttoyourhealththanyoumayrealize.[A]MeganJoneskne
A、TheUS.B、Italy.C、China.D、Russia.B
随机试题
美国国会有权()
女孩,6岁,突发腹痛11小时,以脐周痛为主,腹痛呈持续性,逐渐加重。发热39℃,排正常粪便1次。查体:患儿腹胀,全腹有明显压痛及肌紧张,移动性浊音(+),肠鸣音消失。血常规:WBC19×109/L,中性粒细胞0.9。为进一步明确诊断,下列哪项检查最有意
固定总价合同适用于在()的情况下采用。
以下情形中,中国证监会可以对有关责任人员采取终身的证券市场禁入措施的有()。Ⅰ.从事保荐业务,负有法定职责的人员,故意不履行法律、行政法规或者中国证监会规定的义务,并造成特别严重后果的Ⅱ.严重违反法律、行政法规或者中国证监会有关
下列关于债券市场的功能,表述正确的有()。
某中学语文老师郭某刚走上工作岗位,她非常在意学生对自己的看法,每次上完课都会问学生:“你们喜不喜欢郭老师?”郭老师所处的教师专业发展阶段是()。
以下和“太阳和金子是会发光的”判断不相同的是()。
有人说,怀旧是人年老的表现。我总觉得怀旧是一种非常美好的情愫,是有一定文化修养和历史审美意识的体现。令我奇怪的是中国人怀旧尚且可以懂得,怎么外国人也怀旧?而且不分老少都跑到中国来怀旧。他们到中国旅游专门找那些交通不便、偏僻荒疏、无人问津的陈年老屋、破旧古院
DisagreementmarkshistoricalappraisalsofAmerica’semergenceasagreatpowerattheturnofthetwentiethcentury.Ontheo
TheAmericanideaofrespectinghumanrightscamefromseveralsources.First,thecolonistshadbeen【B1】______oftheirrightsi
最新回复
(
0
)