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
The biosphere is the name biologists give to the sort of skin on the surface of this planet that is inhabitable by living organi
The biosphere is the name biologists give to the sort of skin on the surface of this planet that is inhabitable by living organi
admin
2013-01-10
25
问题
The biosphere is the name biologists give to the sort of skin on the surface of this planet that is inhabitable by living organisms. Most land creatures occupy only the interface between the atmosphere and the land; birds extend their range for a few hundred feet into the atmosphere; burrowing invertebrates such as earthworms may reach a few yards into the soil but rarely penetrate farther unless it has been recently disturbed by men. Fish cover a wider range, from just beneath the surface of the sea to those depths of greater than a mile inhabited by specialized creatures. Fungi(真菌) and bacteria are plentiful in the atmosphere to a height of about half a mile, blown there by winds from the lower air. Balloon exploration of the stratosphere (同温层) as long ago as 1936 indicated that moulds and bacteria could be found at heights of several miles, recently the USA’s National Aeronautics and Space Administration has detected them, in decreasing numbers, at heights up to eighteen miles. They are pretty sparse at such levels, about one for every two thousand cubic feet, compared with 50 to 100 per cubic foot at two to six miles (the usual altitude of jet aircraft), and they are almost certainly in an inactive state. Marine bacteria have been detected at the bottom of the deep Pacific trench, sometimes as deep as seven miles; they are certainly not inactive. Living microbes have also been obtained on land from cores of rock drilled (while prospecting for oil) at depths of as much as 1,200 feet. Thus we can say, disregarding the exploits of astronauts, that the biosphere has a maximum thickness of about twenty-five miles. Active living processes occur only within a compass of about seven miles, in the sea, on land and in the lower atmosphere, but the majority of living creatures live within a zone of a hundred feet or so. If this planet were scaled down to the size of an orange, the biosphere, at its extreme width, would occupy the thickness of the orange-colored skin, excluding the pith.
In this tiny zone of our planet takes place the multitude of chemical and biological activities that we call life. The way in which living creatures interact with each other, depend on each other or compete with each other, has fascinated thinkers since the beginning of recorded history. Living things exist in a fine balance which is often taken for granted—for, from a practical point of view, things could not be otherwise. Yet it is a source of continual amazement to scientists because of its intricacy and delicacy. The balance of nature is obvious most often when it is disturbed, yet even here it can seem remarkable how quickly it readjusts itself to a new balance after a disturbance. The science of ecology—the study of the interaction of organisms with their environment—has grown up to deal with the minutiae of the balance of nature.
According to the text, the balance of nature is ______.
选项
A、something which we should not take for granted
B、most frequently apparent when it is upset
C、only now becoming of interest to scientists
D、very difficult to preserve
答案
B
解析
第二段中“The balance of nature is obvious most often when it is disturbed”可知正确答案,因为apparent和obvious,upset和disturbed都是同义词。
转载请注明原文地址:https://kaotiyun.com/show/o4TO777K
0
研究生英语学位课统考(GET)
相关试题推荐
Theoceansformthe______oftheearth’ssurface.
______theassignmentsareturnedinbeforetheendofthisweek.
Ifyoulookatthematteranalytically,youidentifytwopartsoftheproblem:Thereis,ofcourse,thematterof"time",which
ThedevelopmentandwidespreaduseofcomputertechnologyandtheInternethavetransformedhowwecommunicate,howwecommunica
ThestatisticsI’vecitedandthelivingexamplesarealltoofamiliartoyou.Butwhatmaynotbesofamiliarwillbetheincre
Sherememberedseveraloccasionsinthepast______shehadexperiencedasimilarfeeling.
Alittlemorethanacenturyago,MichaelFaraday,thenotedBritishphysicist,managedtogainaudiencewithagroupofhighgo
(北京航空航天大学2013年试题)Mostworthwhilecareersrequiresomekindofspecializedtraining.Ideally,therefore,thechoiceofan【C1】
Youmustletmehavetheannualreportwithout______byteno’clocktomorrowmorning.
Sequoyahwasbornabout1770inthevillageofTaskigi.HewasaCherokeeIndian,and,alongwithhisentiretribe,hewasillit
随机试题
在Excel工作表中,假设A2=7,B2=5.6,选择A2:B2区域,并将鼠标指针放在该区域右下角填充句柄上,拖动至E2,则E2=()
胸部外伤后,胸壁软化(浮动肋)的发病原因是
当定期检查中出现状况值为3或4的项目,且其产生原冈及详细情况不明时,应做专项检查。()
区域经济与宏观经济影响分析应立足于项目的实施能够促进和保障经济有序高效运行和可持续发展,分析重点应是项目与区域发展战略和国家长远规划的关系。下列内容分别属于直接贡献和间接贡献的是()。
甲乙签订一份买卖合同,约定违约方应向对方支付18万元违约金。后甲违约,给乙造成损失15万元。根据合同法律制度的规定,下列说法正确的是()。
我国第一个被列入《世界遗产名录》的皇家园林是指()。
(1)影响人类生活(2)引发沙尘暴(3)中长距离输送(4)强上升气流作用(5)粉沙、细土和微尘飞扬
不同利益群体在特定体制中所受束缚与保护的程度是不同的,相对而言,束缚少而保障多的群体会觉得体制公平,反之会觉得不公平进而要求变革。转轨过程的情况与此类似,某类群体摆脱的束缚多于失去的保障,甚至是只摆脱束缚而不失去保障,他们会拥护改革并认为它公平;相反,摆脱
根据我国《刑法》的规定,下列情形属于没收财产刑范围的是()。
设f(x)在[0,1]有连续导数,且f(0)=0,令,则必有
最新回复
(
0
)