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
Electromagnetic Energy 1 White light seems to be a combination of all colors. The energy that comes from a source of light i
Electromagnetic Energy 1 White light seems to be a combination of all colors. The energy that comes from a source of light i
admin
2014-05-13
36
问题
Electromagnetic Energy
1 White light seems to be a combination of all colors. The energy that comes from a source of light is not limited to the kind of energy you can see. Heat is given off by a flame or an electric light. On a cloudy day it is possible to get a sunburn even though you feel cool. Visible light and the kinds of energy that produce warmth and sunburn are examples of electromagnetic energy.
2 The sun is 93 million miles from the earth. Yet we can use energy from the sun because electromagnetic energy travels through space.
3 Many other kinds of energy are also types of electromagnetic energy. Radio, television, and radar signals travel from transmitters to receivers as low-energy electromagnetic waves. Infrared(红外线的)radiation is an electromagnetic wave. When it is absorbed by matter, heat is produced. Waves of infrared and visible light have more energy than waves of radio, television, or radar. Ultraviolet rays(紫外线)and X-rays are electromagnetic waves with even greater amounts of energy. Infrared radiation is used in cooking food and heating buildings. Sunlight and electric lights are part of our requirements for normal living. Ultraviolet radiation is useful in killing certain disease organisms. X-rays and gamma rays have so much energy that they travel through solid objects. They can be used to detect and treat cancer. X-rays are used in industry to find hidden cracks in metal, and in medicine to reveal broken bones.
4 Usually we use electricity to generate electromagnetic energy. The source of most of our energy is the sun. Heat from the sun causes water to evaporate. When the water falls to the earth as rain, some of it is trapped behind dams and then used to operate electric generators. Other generators are powered by coal, but the energy stored in coal came from the sun, too.
5 Until recently, the source of the tremendous amount of energy given off by the sun was a puzzle. If the sun depended on chemical reactions, it would have used up all its energy long ago. Experiments with electromagnetic radiation led to the theory that mass can be converted into energy. About forty years after the theory was proposed, nuclear energy was harnessed(利用)by man. Chemical energy comes from electron(电子)rearrangement. Nuclear energy comes from a change in the nucleus of an atom. Compared with chemical reactions, nuclear reactions release millions of times more energy per pound of fuel. We now believe that the sun’ s energy comes from the nuclear reactions in which hydrogen is changed into helium(氦).
6 Nuclear energy is beginning to compete with coal as an economical source of power to generate electricity. It is also being used to operate engines in large ships. Scientists continue to seek new and better methods of obtaining and using energy.
A. Nuclear Reactions as the Uasting Source of the Sun s Energy
B. The Most Important Source of Energy
C. Types of Electromagnetic Energy
D. The Machines Used for Energy Generation
E. Seeking New Sources of Energy
F. The Use of Ultraviolet Radiation in Medicine
Paragraph 5
选项
答案
A
解析
第五段开头提到太阳能的来源仍是个谜,随后对此进行了分析,最后得出太阳能来自核反应释放的能量。由此可知,第五段主要讲的是,氢原子转变为氦原子的核反应释放的能量是太阳能的来源。几个选项中只有A项提到核反应是太阳能的持久来源,因此选择A项。
转载请注明原文地址:https://kaotiyun.com/show/8OQd777K
本试题收录于:
职称英语理工类B级题库职称英语分类
0
职称英语理工类B级
职称英语
相关试题推荐
Inprevioustimes,whenfreshmeatwasinadequate,pigeonswerekeptbymanyhouseholdsasasourceoffood.
GlucosecannotbeturnedintoenergyinthebodyTheworsteyedamageinducedbydiabetesis
GlucosecannotbeturnedintoenergyinthebodyWithdiabeticretinopathy,thedamagedbloodvesselsintheretina
Accordingtothepassage,apersonsufferingfromcancerwillAccordingtotheNewYorkTimes’report,acombinationoftwonew
Accordingtothepassage,apersonsufferingfromcancerwillAccordingtotheNewYorkTimes’report,acombinationoftwonew
DebateovertheUseofRenewableEnergyAmusableofRockefellerUniversityinNewYork,USsaysthekeyrenewable(可再生的)ene
DebateovertheUseofRenewableEnergyAmusableofRockefellerUniversityinNewYork,USsaysthekeyrenewable(可再生的)ene
随机试题
衡量婴幼儿体格生长的重要指标是()。
急性链球菌感染后肾小球肾炎的病理类型为:()
试述子宫收缩的三大特点。
影响药物吸收的因素中,不正确的是
排水系统主要包括( )。
根据民事法律制度的规定,下列纠纷中,诉讼时效期间为1年的是()。
C公司2011年发生下列业务:(1)偿还短期借款,本金2000万元,利息10万元;(2)偿还长期借款,本金5000万元,应付利息66万元,其中资本化利息费用60万元;(3)支付到期—次还本付息的应付债券,面值1000万元,3年期,利率5%;(4)支
沿一个平面将长、宽和高分别为8、5和3厘米的长方体切割为两部分,问两部分的表面积之和最大是多少平方厘米?
Mostchildrenatthetenderageofsixorsoarefullofthemostimpracticalschemesforbecomingpolicemen,firemenortraind
A、Iwenttothelibrary.B、IusuallywatchTV.C、Sorry,Idon’tknow.D、Idon’tliketheprogram.B本题考查由How引导的特殊疑问句的回答。题目问:“你如何打
最新回复
(
0
)