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
44
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.
The passage says that the biosphere ______.
选项
A、extends only 1,200 feet below the earth’s surface
B、is about seven miles in width
C、is as much as twenty-five miles in thickness
D、is a zone only about one hundred feet wide
答案
C
解析
根据原文“Thus we can say…that the biosphere has a maximum thickness of about twenty-five miles.”可知,选项C所提到的“生物圈最大厚度约25英里”是正确的。
转载请注明原文地址:https://kaotiyun.com/show/E4TO777K
0
研究生英语学位课统考(GET)
相关试题推荐
Mr.Danewentthroughhisdaughter’sessaycarefully,toeliminateslangwordsfromit(2004年秋季电子科技大学考博试题)
Themotheristoldthatherchildisdesperatelyill—thechancesofsurvivalareslim,andthetreatmentisasdreadfulasthe
I’msorryto______youwhileyouareworking,butImustaskyouaquestionaboutEnglish.
Ingeneral,matterswhichlieentirelywithinstatebordersarethe______concernofstategovernments.(2013年北京航空大学考博试题)
Sheonceagainwentthroughhercompositioncarefullyto______allspellingmistakesfromit.
Planningisaveryimportantactivityinourlivesyetreallysophisticated.Itcangivepleasure,evenexcitement,【C1】______ca
随着我国社会经济的迅猛发展、人民生活水平的提高和医疗卫生事业的改善,我国老年人口明显增多。不少人对此忧心忡忡。但有识之士指出,我们不仅要看到人口老龄化所带来的巨大压力,也要看到人口老龄化背后所蕴涵的商机以及老年人丰富的智力、经验等资源,要将压力变为机遇。
Averyimportantworldproblemistheincreasingnumberofpeoplewhoactuallyinhabitthisplanet.Thelimitedamountoflanda
Averyimportantworldproblemistheincreasingnumberofpeoplewhoactuallyinhabitthisplanet.Thelimitedamountoflanda
Sherememberedseveraloccasionsinthepast______shehadexperiencedasimilarfeeling.
随机试题
智慧城市是一个由许多相互联系、相互依存、相互制约的因素构成的复合巨系统。依据构成因素地位和作用的不同,智慧城市系统主要包括五个子系统:战略系统、经济活动系统、社会活动系统、信息系统和空间系统。智慧城市的建设规划,应注意加强对智慧城市发展战略的研究,重视智慧
教师从不同的角度使儿童得到完整的印象的示范形式属于()
佝偻病发病的主要病因是()
下列各项,具有大补元气功效的药物是
某产妇,产后第4天,体温38℃,子宫体轻压痛,恶露量多且臭。最可能的诊断是
在中国现代文坛上,以诗歌为主的作家是()。
TheEU’sclimatechiefisseekingtoextendthebloc’srenewableenergytargets,inamoveapparentlydesignedtoprotectthegr
在学生表中共有100条记录,执行如下命令,执行结果将是INDEXON-总分TOZFSETINDEXTOZFGOTOPDISPLAY
Readthetextbelowaboutsupplychain.Inmostofthelines41—52thereisoneextraword.Itiseithergrammaticallyincorrect
A、Michelle’sbrotherranawayfromhome.B、Michelle’smotherhadanotherbaby.C、Michellemarriedthelandlordofalocalpub.D
最新回复
(
0
)