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
21
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 writer says that ecology is primarily concerned with the ______.
选项
A、finer details of the balance of nature
B、role of organisms in the environment
C、way living creatures compete with each other
D、way nature readjusts to a new balance
答案
A
解析
从最后一句话“The science of ecology…has grown up to deal with the minutiae of the balance of nature.”可找到答案。minutiae表示details的意思。
转载请注明原文地址:https://kaotiyun.com/show/s4TO777K
0
研究生英语学位课统考(GET)
相关试题推荐
Itwasdifficulttoseethroughthe______fog.
Thisschoolis______;onlyverybrightchildrenareadmitted.
Jackis______abouthischancesofwinningagoldmedalattheOlympicsnextyear.
TheUniversityinTransformation,editedbyAustralianfuturistsSohailInayatullahandJenniferGidley,presentssome20highly
Itwasaverydifficultexamination,______hepasseditwithdistinction.
Althoughspeechandwritingarethespecialmeansofcommunicatingofhumans,theinterchangealsotakesplaceinmanyotherway
Asitturnedouttobeasmallhouseparty,we______soformally.(北京大学2008年试题)
Youmustletmehavetheannualreportwithout______byteno’clocktomorrowmorning.
随机试题
试述《多边备忘录》对协助请求的规定内容。
基础代谢率
最易触及心包摩擦感的是
熟地价包括土地使用权出让金、城市环保设施建设费和土地开发费。()
在结构设计中,一般要遵守的原则是()。
下列会导致标书失效的偏差是()。
—Jack,youerasetheblackboardtoday,________?—ButIdidityesterday.
阅读以下文字,完成以下问题。语言体现的是一种文化,网络语言是时代发展过程中一种特定的语言现象。传统语言的表达已不足以将信息转变成最简洁的形式输入输出,于是,有别于中国传统语言的网络浯言[],并以惊人的速度迅速普及和在社会中传播。网络语言
Oneofthemostimportantresultsofresearchintoageinghasbeentopinpointthesignificanceofshort-termmemory.Thisfacul
Theindustrialsocietieshavebeenextremelyproductiveduringthelasttwocenturies.Theeconomicadvancehasbeen【C1】______
最新回复
(
0
)