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
Atmosphere 1.The atmosphere is a mixture of several gases. There are about ten chemical elements which remain permanently in gas
Atmosphere 1.The atmosphere is a mixture of several gases. There are about ten chemical elements which remain permanently in gas
admin
2009-06-15
62
问题
Atmosphere
1.The atmosphere is a mixture of several gases. There are about ten chemical elements which remain permanently in gaseous form in the atmosphere under all natural conditions. Of these permanent gases, oxygen makes up about 21 percent and nitrogen about 78 percent. Several other gases, such as argon (氩), carbon dioxide, hydrogen, neon (氖), krypton (氪), and xenon (氙), comprise the remaining one percent of the volume of dry air. The amount of water vapor, and its variations in amount and distribution is of extraordinary importance in weather changes. Atmospheric gases hold in suspension (悬浮) great quantities of dust, pollen (花粉), smoke, and other impurities which are always present in considerable, hut variable amounts.
2.The atmosphere has no definite upper limits but gradually thins until it becomes imperceptible (感觉不到的). Until recently it was assumed that the air above the first few miles gradually grew thinner and colder at a constant rate. It was also assumed that upper air had little influence on weather changes. Recent studies of the upper atmosphere, currently being conducted by earth satellites and missile probings, have shown these assumptions to be incorrect. The atmosphere has three well-defined strata (layers).
3.The layer of the air next to the earth, which extends upward for about ten miles, is known as the tropophere (对流层). On the whole, it makes up about 75 per cent of all the weight of the atmosphere. It is the warmest part of the atmosphere because most of the solar radiation is absorbed by the earth’s surface which warms the air immediately surrounding it. A steady decrease of temperature with increasing elevation is a most striking characteristic. The upper layers are colder because of their greater distance from the earth’s surface and rapid radiation of heat into space. The temperatures within the troposphere decrease about 3.5 degrees per 1,000 feet increase in altitude (海拔高度). Within the troposphere, winds and air currents distribute heat and moisture. Strong winds, called jet streams, are located at the upper levels of the troposphere. These jet streams are both complex and widespread in occurrence. They normally show a waveshaped pattern and move from west to east at velocities (速度) of 150 mph, but velocities as high as 400 mph have been noted. The influences of changing locations and strengths of jet streams upon weather conditions and patterns are no doubt considerable. Current intensive research may eventually rebel their true significance.
4.Above the troposphere to a height of about 50 miles is a zone called the stratosphere (高温层). The stratosphere is separated from the troposphere by a zone of uniform temperatures called the tropopause (对流层顶). Within the lower portions of the stratosphere is a layer of ozone (臭氧) gases which filters (过滤) out most of the ultraviolet rays from the sun. The ozone layer varies with air pressure. If this zone were not there, the full blast of the sun’s ultraviolet light would burn out skins, blind our eyes, and eventually result in our destruction. Within the stratosphere, the temperature and atmospheric composition are relatively uniform.
5.The layer upward of about 50 miles is the most fascinating but the least known of the three strata. It is called the ionosphere (电离层) because it consists of electrically charged particles called ions, thrown from the sun. The northern lights (aurora borealis) originates within this highly charged portion of the atmosphere. Its effect upon weather conditions if any, is as yet, unknown.
选项
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/V3hd777K
本试题收录于:
职称英语理工类基础题库职称英语分类
0
职称英语理工类基础
职称英语
相关试题推荐
Sinceancienttimespeoplehavefoundvariouswaystopreservemeat.
EverybodywasgladtoseeMaryback.
Whenpeoplewithdepressiontriedtostopsmokingtheyare______.Thedepressedsmokersoftenusetobaccoto______.
Thepassageismainlyabout______.Thepassageimpliesthataslowingininflationwouldhave______effectonmedicalcosts.
Accordingtothepassage,whichofthefollowinghaschangedthemostinthelast500years?"Some"inthelastsentenceofthe
Themainideaofthispassageisthat______.Ifpeopledon’tstopsmoking,theywill______.
A.NecessityfordevelopingadulteducationB.EarlydaysofadulteducationC.WaysofreceivingadulteducationD.Growthofa
A.NecessityfordevelopingadulteducationB.EarlydaysofadulteducationC.WaysofreceivingadulteducationD.Growthofa
Over-the-counterdrugsarethemedicines______.Thenewrequirementsfortheactivechemicalsinamedicinemustbelabelled_
HomeSchoolingAllchildrenintheUnitedStateshavetoreceiveaneducation,butthelawdoesnotsaytheyhavetobeeducated
随机试题
胃幽门部
在低浓度时为抑菌剂,高浓度时可有杀菌作用的是
在中国古代,主流的治国理念是()
男性,70岁。高血压病史6年。今晨起床后突然头痛、烦躁、多汗、面色苍白,血压250/125mmHg,心率125次/分,律齐,双肺布满中、小水泡音和少量哮鸣音,肝脾未及,双下肢无浮肿。诊断急性左心衰,最有临床诊断意义的是
阿米卡星属于
下列涂料原料中属于次要成膜物质的有()。
Everybodylovesafatpayrise.Yetpleasureatyourowncanvanishifyoulearnthatacolleaguehasbeengivenabiggerone.I
分区分配内存管理方式的主要保护措施是()。
设矩阵A的伴随矩阵A*=,且ABA-1=BA-1+3E,求B.
(66)means“Any HTML document on an HTTP Server”.
最新回复
(
0
)