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
24
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.
Inprevioustimes,whenfreshmeatwasinadequate,pigeonswerekeptbymanyhouseholdsasasourceoffood.
GlucosecannotbeturnedintoenergyinthebodyTheworsteyedamageinducedbydiabetesis
Accordingtothepassage,apersonsufferingfromcancerwillAccordingtotheNewYorkTimes’report,acombinationoftwonew
DebateovertheUseofRenewableEnergyAmusableofRockefellerUniversityinNewYork,USsaysthekeyrenewable(可再生的)ene
DebateovertheUseofRenewableEnergyAmusableofRockefellerUniversityinNewYork,USsaysthekeyrenewable(可再生的)ene
DebateovertheUseofRenewableEnergyAmusableofRockefellerUniversityinNewYork,USsaysthekeyrenewable(可再生的)ene
随机试题
“坐位体前屈”指标一般只限于4岁以上的儿童。()
提出语言遗传机制假设的是()
治疗慢阻肺的茶碱类支气管舒张剂的主要不良反应是()。
中国公民王某上街购物,被某国领事馆车辆撞伤,王某即向当地人民法院起诉,请求赔偿损失。本案适用()。
发包方根据建设项目的特点、项目进展情况和控制目标的要求等因素,将建设项目按照一定原则分解,将设计任务分别委托给不同的设计单位,将施工任务分别发包给不同的施工单位,各设计单位和施工单位分别与发包方签订合同,此种模式是( )。
沥青混凝土路面面层的材料组成有()。
()年中国人民银行对银行业金融机构的监管职责移交至新设立的银监会。
20世纪20年代至50年代,西方教育心理学吸取了儿童心理学和心理测验方面的成果,大大扩充了自己的内容。这一时期,教育心理学内容丰富,并成为一门具有独立理论体系的学科。
A、正确B、错误A
ThepassageismainlyaboutthemassprogressandpresenttroubleofhealthysportindustryinIndia.Notallhealthclubsare
最新回复
(
0
)