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
During the early period of the earth’s history, the weather on earth apparently fluctuated between bright sun and showers. In re
During the early period of the earth’s history, the weather on earth apparently fluctuated between bright sun and showers. In re
admin
2010-06-30
72
问题
During the early period of the earth’s history, the weather on earth apparently fluctuated between bright sun and showers. In recent times, however, the mountains and valleys on land and under water have had a great influence on the earth’s weather. They effect the movements of the thin film of water we call the sea and the thin layer of air around the earth. These movements produce changes in the temperature and humidity prevailing at the surface.
Although the sun is approximately 93 million miles away, its rays warm the earth. The areas that receive the sun’s rays vertically are, naturally, warmer than those areas that receive only slanting rays. 【61】
Vertical rays do not need to make as long a journey through the atmosphere before reaching the surface of the earth. Therefore, less of their heat is lost in the air and more of their heat is saved to warm the earth. Furthermore, slanting rays are spread over available at a given point.
The sun’s rays do not heat the vast stretches of space between the sun and the earth. 【62】
If they did, we should expect to be warmer on top of a high mountain or riding in an airplane than we are on the ground.
Actually, however, we feel cooler at the top of a mountain; and, if we fly a plane high enough, we encounter freezing temperatures, even over the equator.
This is true because the sun’s rays are like the waves used in radio broadcasting. Music sent out by a radio transmitter does not fill the air with sounds for all to hear. Instead, the music travels in the form of electromagnetic waves, which must pass through a receiver and an amplifier to be heard. 【63】
Similarly, the sun’s rays cross our atmosphere and are absorbed by the surface of the earth. These rays warm the surface, which sends back some of this heat into the air.
When the air near the earth’s surface has been warmed, it rises and is replaced by cooler air which comes down to take its place. This cool air, in turn, is warmed and rises to be replaced by more cool air. As air rises it becomes cooler because it expands and is less concentrated, the air is suddenly let out of a tire, the air expands rapidly and becomes much cooler. On the other hand, when air is put under greater pressure, it becomes warmer. This is what happens to the cold air that comes down to take the place of rising warm air.
The earth is much cooler than the sun, and the wave length of the earth’ s radiations is much longer than that of sun rays. 【64】
These longer heat waves cannot pass through the atmosphere as easily as the short waves coming from the sun.
【65】
Similarly, radio stations that transmit programs to distant countries broadcast in short waves, which can travel all round the world.
Stations that broadcast local programs send out longer waves, which can be received more easily, but only in a limited area.
【65】
选项
答案
同样,电台用短波把节目输送到距离较远的地方,到达世界上各个角落。
解析
转载请注明原文地址:https://kaotiyun.com/show/qQJd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
YouwillhearaconversationbetweenMissGreen,aneducationaljournalist,andProfessorWilson,anexpertineducationalstudi
Onedayagroupofpeoplewalkedintoacaveandpaintedhandprintsalloverthewalls.Tenthousandyearslater,archaeologists
Youmaysaythatthebusinessofmarkingbooksisgoingtoslowdownyourreading.【C1】______probablywill.That’soneofthe【C2
Surgeonswillsoonbeabletoentertheeyetocarryoutoperations--atleastinavirtualsense.Techniquesderivedfromvirtua
Surgeonswillsoonbeabletoentertheeyetocarryoutoperations--atleastinavirtualsense.Techniquesderivedfromvirtua
Wehaveescapedthebattlefieldandnowcan,withmodemguidancesystemonmissies,touchvirtuallyeverysquareyardoftheea
WhenhediesinAprilof1983,Dr.JoelHildebrandwas101yearsold,whohadbeenmarriedforseventy-fiveyears,andhadtaugh
Amultinationalcorporationisacorporateenterprise,whichthoughheadquarteredinonecountry,conductsitsoperationsthroug
InwhattimeoftheyeardidwealthyRomansliketovisitPompeii?
随机试题
电流互感器将接有仪表和继电器的低压系统与________隔离。利用电流互感器可以获得保护装置和仪表所需的电流。
心肌梗死的好发部位和类型。
声强的定义为
失血性休克时采取的体位是:
治疗暑湿袭表证之高热,应首选
小李的户籍所在地为乙市A区,但其经常居住于甲市A区,小李为科贸有限责任公司的股东,科贸有限责任公司位于甲市B区,后小李因对科贸有限责任公司的利润分配存在不满欲向法院提起诉讼,则对于该诉讼可能具有管辖权的法院是:()
关于个人独资企业投资人及其债务责任的下列表述中,正确的是()。
公司增发的普通股的市价为12元/股,筹资费用率为市价的6%,本年发放股利每股0.6元,已知同类股票的预计收益率为11%,则维持此股价需要的股利年增长率为()。
A社区是一个新建小区,社区内儿童比较多,但是场所有限,难以开展活动。与这个社区相邻有一所学校。暑假期间,社区的工作者与学校管理者相互协调,以学校为活动场所,组织社区青少年开展了多项活动。A社区与学校的联合运用了()的社区资源连接方式。
去年同期全市接待入境游客()万人次上半年,全市完成基础设施投资与去年同期相比增加了()亿元
最新回复
(
0
)