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
2015-01-09
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(无 脊椎动物)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 arc 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 sealed 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, 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
A
解析
推理题。解题点在第二段。文中提到“Living things exist in a fine balance which is often taken forgranted…,”以及后面的生物圈经常因为其复杂和精妙给科学家带来惊奇,可知生物圈的平衡不是理所当然的,就是A项中something which we should not take for granted的意思,所以正确答案是A选项。
转载请注明原文地址:https://kaotiyun.com/show/NcQO777K
0
考博英语
相关试题推荐
Manyinstructorsbelievethataninformal,relaxedclassroomenvironmentis【C1】______tolearningandinnovation.Itisnotuncom
Manyinstructorsbelievethataninformal,relaxedclassroomenvironmentis【C1】______tolearningandinnovation.Itisnotuncom
Thesimplestanimalsarethosewhosebodiesaresimplestinstructureandwhichdothethingsdonebyalllivinganimals,sucha
TheclimateofEarthischanging.Climatologistsareconfidentthatoverthepastcentury,theglobalaveragesurfacetemperatur
Theenergycrisis,whichisbeingfeltaroundtheworld,hasdramatizedhowthecarelessuseoftheearth’sresourceshasbrough
Pioneermenandwomenenduredterriblehardships,and______.
Rightsandobligationsare______;anobligationflowsfromaright,andthisprovidesclarityinaction.Forexampleifitcanb
Discoveriesingenetics,molecularbiologyandgenomics—allof______providesignificantbenefitsforhumanhealth—wouldnotbe
Therearethreeseparatesourcesofhazard【1】totheuseofnuclearreactiontosupplyuswithenergy.Firstly,theradioactivem
Prof.Wardhardlyeverwentto______thetheater.
随机试题
透明软骨的软骨细胞的结构和功能不包括
A.带蹬吊带法B.手法复位,石膏固定C.骨盆截骨(Salter)术切开复位D.骨盆内移截骨(Chiari)术6个月小儿先天性髋脱位的治疗可用
患者,男,18岁。足球赛后右膝关节疼痛,行走时交错。体检:右膝关节肿胀,外侧压痛明显。本病最可能损坏的结构是
土石坝下游有渗漏水出逸,在附近设导渗沟,用直角三角形水堰测其明流流量,实测堰上水头为0.3m,按《土石坝安全监测技术规范))(SL60—1994)提供的计算方法,该处明流流量为()。
附注是财务报表不可或缺的组成部分。()
我国儿童文学的最高奖项是()。
“大漠孤烟直,黄河落日圆”描绘的是这样的景象:极目大漠,只见一缕孤烟,冲霄直上;遥望长河,一轮落日浮动河面,显得格外浑圆。请问这句诗出自哪位诗人的哪首诗?()
下列名言中,与“千里之堤,溃于蚁穴”包含同一哲理的是()
有以下表:读者(借书证号C,姓名C,单位C,性别L,职称C,联系电话C)说明:"性别"值为逻辑真表示男。查询性别为男(字段值为逻辑真)、职称为教授或副教授的读者信息,正确的SQL语句是:
AJOBWITHRISKSHaveyoueverbeentothecinemaandwonderedinamazement.how AMAZEfilmstarsmanaget
最新回复
(
0
)