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
An eagle wheels overhead against a crystalline blue sky, Martin Flanagan walks toward a grove of towering cottonwood trees besid
An eagle wheels overhead against a crystalline blue sky, Martin Flanagan walks toward a grove of towering cottonwood trees besid
admin
2015-01-30
55
问题
An eagle wheels overhead against a crystalline blue sky, Martin Flanagan walks toward a grove of towering cottonwood trees beside the Yellowstone River, which is the color of chocolate milk due to the spring rain.
As Mr. Flanagan leaves the glaring sun of the prairie and enters the shady grove, his eyes search for a specific tree. As he reaches a narrow-leaf cottonwood, a towering giant, he cranes his neck to look at the top. "This is the one I plan to nominate for state champion," he says, petting the bark with his hand. "It’s beautiful isn’t it?"
When Europeans first came to North America, one of the largest primeval forests in the world covered much of the continent. Experts say a squirrel could have traveled from the Atlantic coast to the Mississippi River without touching the ground. But only about 3 percent of America’s native old-growth forest remains, and many of the trees they hold are those that were not big enough to attract a logger’s eyes. The result is a generation of trees that barely resemble the native forests that once covered the country.
That makes some scientists suspect that the surviving forests have lost much of their genetic quality, the molecular muscle that made them dominate the landscape. When the loggers swept through, these scientists say, only poor specimens were left to reproduce. Other researchers wonder whether environmental factors or just plain luck may explain a good part of the supertrees’ success.
To answer those questions, the mightiest trees of their types, or genetically identical offspring, must be preserved for study, and that is what is being done by a handful of enthusiasts, including Mr. Flanagan and David Milarch, a nurseryman from Copemish, Mich. They are searching out the largest tree of each species and taking cuttings of new growth to make copies of genetic clones of the giants. With tissue culture and grafting, they have reproduced 52 of the 827 living giants and are planning the offspring in what they call "living libraries." More than 20,000 offspring have been planted.
Directions: Complete the following sentences with information given in the passage in a maximum of 10 words for each blank.
In the days when Europeans first came to America, it had one of the______.
选项
答案
largest primeval forests in the world
解析
转载请注明原文地址:https://kaotiyun.com/show/hKVK777K
本试题收录于:
C类竞赛(非英语专业本科)题库大学生英语竞赛(NECCS)分类
0
C类竞赛(非英语专业本科)
大学生英语竞赛(NECCS)
相关试题推荐
A、Throughspeaking.B、Throughlistening.C、Throughreading.D、Throughwriting.B由原文可知,男士主要是通过听力学到了一点日语。因此答案为B。
SuggestionsforEffectiveResearch-basedAssignmentsIntroduction.well-designedassignments—teachstudentsvaluab
MakeYourHolidaysMoreMeaningfulⅠ.Whattodobeforetheholidayseason1)【T1】________aweeklycalendar2)start
________touchinginO’Henry’sstoriesisthegallantrywithwhichordinarypeoplestruggletomaintaintheirdignity.
Takingondebtisoneofthemostimportanteconomicdecisionsapersoncanmake.Borrowingtoinvestineducationcanyieldal
Coffeeismadefromthebeansthatgrowinthefruitofthecoffeeplant.Thereare【16】usu______twobeansineachpodoffruita
Roadpolitenessisnotonlygoodmanners,butgoodsensetoo.Ittakesthemostcool-headedandgood-temperedofdriversto【C1】_
Roadpolitenessisnotonlygoodmanners,butgoodsensetoo.Ittakesthemostcool-headedandgood-temperedofdriversto【C1】_
Roadpolitenessisnotonlygoodmanners,butgoodsensetoo.Ittakesthemostcool-headedandgood-temperedofdriversto【C1】_
RainforestsmakeupaboutsixpercentoftheEarth’ssurfaceandtheyareveryimportanttous.Theyprovideuswithmuchofthe
随机试题
某项专利技术的法定保护期自2008年1月15起15年,2010年1月15目作为评估基准日,预计在2018年1月会有更新的技术替代该专利技术并在生产上得到广泛运用,该专利技术的预期收益期限较为合理的年限为()
根据我国相关法规的规定,对于自身不能怀孕的妇女,医师可协助实行代孕。()
(2004年第89题)在我国,急性胰腺炎的原因主要是
女性,46岁,乙型肝炎十余年,腹胀6个月,腹痛、伴发热10余天,体重减轻,肝大肋下1.0cm,脾未及,移动性浊音阳性,腹腔积液检查:黄色透明,比重1.019,蛋白含量40g,/L,细胞计数550×106/L。最可能的诊断是
咽结合膜热的病原体为
纳税人伪造、变造会计账簿、记账凭证的手段,不缴或者少缴应纳税款,偷税数额占应纳税额的10%以上不满30%,并且偷税数额在1万元以上不满10万元的,应追究的刑事责任为()。
2006年该市流行性乙型脑炎患者多集中在()岁年龄段。2006年该市3岁和6岁流行性乙型脑炎患者的比例最接近()。
甲班与乙班同学同时从学校出发去某公园,学校距离公园96千米。甲班步行的速度是每小时4千米,乙班步行的速度是每小时3千米。学校有一辆汽车,它的速度是每小时48千米,这辆汽车恰好能坐一个班的学生。为了使这两班学生在最短的时间内到达,那么,甲班学生与乙班学生需要
下列关于电子邮件的说法中错误的是________。
WhytheSuper-RichAren’tLeavingMuchofTheirFortunestoTheirKidsA)WhatdoSting,BillGatesandWarrenBuffetthaveinco
最新回复
(
0
)