[00:00.00]Unit 8 Text A
[00:02.25]第八单元 课文A
[00:04.49]Telecommunication via Satellite
[00:06.71]卫星通信
[00:08.93]At the beginning of the twentieth century,
[00:11.31]20世纪初
[00:13.69]there were four powerful means of transmitting and receiving information
[00:17.37]有四种强有力的手段进行远距离的信息传送和接收，
[00:21.05]over long distances:
[00:23.24]它们是
[00:25.42]print,photography,telegraph and telephone.
[00:28.85]印刷、照相、电报和电话。
[00:32.29]By the middle of the century, both radio and television
[00:35.62]到20世纪中叶，无线电和电视
[00:38.95]had become established means of transmitting sounds and/or pictures.
[00:42.63]都已成为公认的传送声音和/或图象的手段。
[00:46.32]In 1964, the Olympic Games in Tokyo
[00:49.89]1964年在东京举行的奥运会
[00:53.47]became the first program to be transmitted via satellite.
[00:56.86]是第一个通过卫星传送的节目。
[01:00.24]In order to transmit an event such as the Olympics via satellite,
[01:04.26]为要通过卫星传送像奥运这样的比赛项目，
[01:08.28]television signals are first changed into radio waves, which are then
[01:12.07]应先把电视信号变成无线电波，
[01:15.86]sent from a station on earth to an orbiting satellite.
[01:18.94]然后从地球上的某个发射站把无线电波送上轨道卫星。
[01:22.02]The satellite receives the radio waves and sends them back to earth,
[01:26.15]卫星收到无线电波，再把它们送回地球，
[01:30.28]where another station picks them up
[01:32.76]由地球上的另一个地面站接收信号，
[01:35.24]and changes them back into television signals.
[01:38.22]并把它产变回电视信号。
[01:41.20]Because any form of sound or visual information
[01:44.28]因为任何形式的声音或图像信息
[01:47.36]can be changed into radio waves,
[01:49.94]都能变成无线电波，
[01:52.51]satellites axe capable of transmitting not only television broadcasts,
[01:56.60]所以卫星不仅能传送电视广播节目，
[02:00.69]but telephone calls and printed materials such as books and magazines.
[02:04.81]还可以传送电话和像书籍、杂志这样的印刷材料。
[02:08.94]The combination of satellites,which transmit information,computers,
[02:12.66]传送信息的卫星存储信息的计算机
[02:16.39]which store information,and television,which displays information,
[02:19.81]和显示信息的电视， 这三者结合起来
[02:23.23]will change every home into an education and entertain merit center.
[02:26.61]能把每家庭变民教育和娱乐中心。
[02:30.00]In theory,every person will have access to an unlimited amount of information.
[02:33.86]理论上说，每个人都能接触无限多的信息。
[02:37.73]Another important use of telecommunication satellites was demonstrated in 1974
[02:42.86]1974年“太空老师”卫星把教育节目
[02:47.99]when the "Teacher in Sky"
[02:50.12]传送给美国边远地区的课堂，
[02:52.25]satellite transmitted educational programs to classes in remote areas of the United States.
[02:56.43]显示了通信卫星的另一个重要用途。
[03:00.61]In 1975,many people in India saw
[03:03.64]1975年，印度有很多人观看
[03:06.67]television for the first time as watched programs about agriculture and health.
[03:10.46]农业节目和健康节目，这是他们第一次看电视。
[03:14.25]The satellite also demonstrated
[03:16.62]卫星还显示了
[03:19.00]how it could provide help to people living in isolated areas where transportation is difficult.
[03:23.27]它怎样向与外界绝少来往的交通不便地区提供帮助。
[03:27.54]For example,
[03:29.07]例如，
[03:30.60]a health worker in an isolated area was able to transmit pictures of a patient's wound
[03:34.78]某一这类地区的保健工作者可以把病人伤情的照片传
[03:38.96] to a doctor far away.
[03:40.88]送给远处的医生。
[03:42.80]He was then able to follow the doctor's instructions
[03:45.78]之后，他就能够根据医生的指示
[03:48.75] on how to care for the patient.
[03:50.88]照顾病人。
[03:53.01]The most common use of telecommunication satellites,
[03:55.53]不过，通信卫星的最通常的
[03:58.05]however,has been for transmitting telephone calls.
[04:00.94]用途还是传送电话。
[04:03.83]Most of them travel 40,000 miles to a satellite and then back to earth.
[04:07.65]大部分电话要走40000英里才能到达卫星然后返回地球。
[04:11.48]Ten years ago,a satellite was capable of receiving and transmitting
[04:14.71]十年前，一个卫星能够同时接收和传送
[04:17.93]more than 33,000 telephone conversations simultaneously.
[04:21.36]33000多对通话。
[04:24.78]Now a single satellite is able to transmit over 100,000 conversations
[04:29.35]现在只要一个卫星就能传送100000多对通话
[04:33.92]as well as several hundred television channels--all at the same time.
[04:37.64]以及数百条电视频道——这一切都是同时进行的。
[04:41.36]Telecommunication can make information
[04:43.89]电信能使人迅速和便捷地
[04:46.41]from around the world available to use quickly and easily,
[04:49.54]利用从世界和地来的信息，
[04:52.68]but some people worry that this may be a risk to our privacy.
[04:56.01]不过有些人担心这会危及我们的隐私。
[04:59.34]If personal information is stored in computers,
[05:02.21]如果计算机中存有私人的信息，
[05:05.08]then it maybe easily transmitted via satellite
[05:07.72]那么只要有人能付服务费，
[05:10.36] to anyone who can pay for the service.
[05:12.84]就可能通过卫星所它传送给这个人。
[05:15.32]Another worry is that telecommunication systems
[05:18.35]人们的另一个担心是电信系统
[05:21.38]may isolate people from each other.
[05:23.72]可能使用彼此不再来往。
[05:26.06]When people are able to shop from their homes,
[05:28.74]当人们在家里就能购物，
[05:31.42]do their banking without leaving the house,
[05:33.74]不出门就能往银行里存钱，
[05:36.07]watch any movie they want on their television,as well as
[05:38.90]在电视上就能看想看的电影，
[05:41.73] get any information they need,
[05:43.92]他们也能得到所需要的任何信息，
[05:46.10]then there will not be as much contact between people.
[05:49.34]那么人们之间的接触就 不会那么多了。
[05:52.57]It is important to realize that the same technology that helps us may also harm us.
[05:56.90]重要的是要能认识到，同一技术既能帮人，也能害人。
[06:01.22]We can prevent this from happening by carefully controlling the new technology.
[06:05.00]我们应该认真控制新技术，防止害人的事情发生。
[06:08.77]As one telecommunication expert says,
[06:11.55]正如一位电信专家说的那样，
[06:14.33]"We must remember that technology alone is not the answer
[06:17.67]“我们必须记住，技术本身不是解决的办法。
[06:21.00]...It is the intelligent application of technology that will lead us to success."
[06:25.02]、、、、、、明智地利用技术才会使我们成功。”

[06:29.04]Text B
[06:30.48]课文B
[06:31.92]What People Don't Know about Air.
[06:33.89]关于空气人们还需要了解些什么
[06:35.86]The air around us is important to everyone.
[06:37.99]我们周围的空气对每个人都是至关重要的。
[06:40.12]Without air, we could not exist.
[06:42.46]没有空气 我们就不能生存。
[06:44.79]Everyone understands that.
[06:46.41]每个人都懂得这一点。
[06:48.03]But air is necessary in many other ways--
[06:50.16]但是空气在许多其它方面也是人所必需的——
[06:52.29]ways that are not always so obvious or widely know.
[06:54.82]这些方面并不是明显和广为人知。
[06:57.36]For example,if we did not have air,there would be no sound.
[07:00.58]比如说，假如我们没有空气，就不会有声音。
[07:03.81]Sound travels through air.Where there is no air,there is no sound.
[07:07.35]声音通过空气传播，没有空气的地方，也就没有声音。
[07:10.89]Without air,there would be no fire.
[07:13.07]假如没有空气，就不会有火。
[07:15.25]There would be no cars or trucks,since motors need air in order to work.
[07:18.64]因为发动机需要空气才能工作，所以也不会有轿车或卡车。
[07:22.02]Without air there would be no wind or clouds.
[07:24.45]没有空气不会有风或云。
[07:26.88]There would be no weather,as we know it.
[07:28.81]正如我们所知，也没有天气。
[07:30.74]The night time would be very cold and the days very hot.
[07:33.47]夜间会很冷，白天会很热。
[07:36.20]We would be forced to seek shelter from the sun,
[07:38.33]我们将被迫寻找地主地方以遮蔽太阳,
[07:40.46]as there would be no atmosphere to protect us from the sun's deadly rays.
[07:43.49]因为没有大气保护我们不受致命的太阳光线的照射.
[07:46.52]The atmosphere is all the air surrounding the earth.
[07:48.79]大气指的是包围着地球的空气.
[07:51.07]Atmospheric pressure is the weight of all that air
[07:53.70]大气压力乃是压在地球表面
[07:56.34]against the surface of the earth.
[07:58.26]的全部空气的重量.
[08:00.18]If we did not have atmospheric pressure,
[08:02.26]假如我们没有大气压力,
[08:04.34]we could not have automobile tires.
[08:06.26]我们便不可能有汽车轮胎.
[08:08.18]The tires would burst if they did not have the pressure of the atmosphere
[08:11.40]因为如果轮胎表面不受到大气压力，
[08:14.63]against their surfaces.
[08:16.21]轮胎就会爆裂。
[08:17.79]Large and powerful,
[08:19.37]大气广大而有力，
[08:20.95]the atmosphere consists of an ocean of gases hundreds of miles high.
[08:24.07]它是由几百英里厚的气体的海洋构成 的。
[08:27.19]It presses down on our bodies
[08:29.02]压在我们身上。
[08:30.85] with a force of more than fourteen pounds per square inch.
[08:33.53]它以每平方英寸14磅以上的力量
[08:36.21]The narrow column of air
[08:37.93]落在我们肩膀 的细空气
[08:39.65]which rests upon our shoulders weighs almost 2,000 pounds.
[08:42.63]柱子几乎重达2000磅。
[08:45.61]But our bodies are built in such a way that this weight does not crush us.
[08:48.80]但是我们的身体构成 使得这个重量不会把我们压坏。
[08:51.98]In this huge ocean of air
[08:53.81]这个巨大的空气海洋中
[08:55.64]there is more energy than in all the coal,oil,and gas we have on earth.
[08:58.81]蕴藏的能量比我们地球上全部的煤、石油和煤气中的能量都多。
[09:01.99]Electrical energy is collected in the atmosphere
[09:04.67]大气中可以收集电能，
[09:07.34]as water is collected and stored in a dam.
[09:09.63]正如同用堤坝惧和存储水一样。
[09:11.92]The existence of electricity in the air has been known for centuries.
[09:14.95]人们知道空气中有电能已经好几百年了。
[09:17.98]Men have gazed in wonder at the bright patterns of lightning in storm clouds.
[09:21.20]他们曾经惊异地注视着闪电在雨云密布的天空上展现耀亮的图案。
[09:24.43]But a thorough study of electricity in the atmosphere
[09:26.96]但在无线电和协达研制出之前，
[09:29.50] was not possible until the development of radio and radar.
[09:32.32]人们不可能对大气中的电进行彻底的研究。
[09:35.14]One scientist,Dr.Sydney Chapman,
[09:37.52]西德尼。查普曼博士是一位科学家
[09:39.89]has tried to explain the electric fieldwhich surrounds the earth.
[09:42.57]他曾试解释地球周围的电场。
[09:45.25]He believes that the great storms on the sun
[09:47.68]他相信强大的太阳风暴
[09:50.11]create large amounts of electric energy.
[09:52.68]能够产生大量的电能。
[09:55.25]This energy is contained in a very light gas called hydrogen.
[09:58.39]它含在一种叫氢气的很轻的气体中。
[10:01.52]The earth pulls the gas toward it,
[10:03.35]地球把氢气吸向它，
[10:05.18]and a ring is formed around the earth
[10:07.15]氢气围绕地球在它表面
[10:09.12]several thousand feet above its surface.
[10:11.30]形成一个几千英尺厚的环。
[10:13.49]The great space ring is a powerful current of electrical energy.
[10:16.57]这个庞大的太空环是一股强大的电流。
[10:19.65]Sometimes the ring comes down and curves into the lower atmosphere,
[10:22.77]有时这个环会下降，弯入在气层的下层，
[10:25.89]musing strange electrical effects.
[10:27.97]从而产生很奇怪的电效应。
[10:30.05]Dr. Chapman's ideas explain many things.
[10:32.41]查普曼博士 的看法对很多现象作出 了解释。
[10:34.78]It has long been known that there is an electric field inside the earth.
[10:37.86]人们早就知道地球内部存在电场。
[10:40.94]It moves in much the same manner
[10:42.77]它的运动方式和大气中
[10:44.60] as the electric energy contained in the atmosphere.
[10:46.92]所含电能的运动方式一样。
[10:49.25]Scientists now believe that the electric energy in the atmosphere
[10:51.98]科学家们现在相信，
[10:54.71]muses the electric energy inside the earth to flow.
[10:57.38]大气的电能引起了地球内部电能的流动。
[11:00.06]If we can learn to control the energy in the atmosphere,
[11:02.40]如果我们能够学会控制大气中的能量，
[11:04.74]we will have an unending supply of energy.
[11:07.17]我们的能源将是取之不尽，用之不竭的。
[11:09.60]Many scientists are trying to learn how to control it.
[11:11.93]很多科学家正在努力了解怎样控制它。
[11:14.27]In the meantime, even those of us who are not scientists
[11:16.90]现在即使我们 这些浊科学家的人
[11:19.52]have begun to pay attention to air.
[11:21.40]也开始注意空气。
[11:23.29]We realize that air does not contain the same elements
[11:25.70]我们认识到，现在空气所含的元素
[11:28.12]that it contained years ago.
[11:29.84]和多年前不一样。
[11:31.57]Automobiles, airplanes, factories,and atomic explosions
[11:35.25]汽车、飞机、工厂以及核工业爆炸
[11:38.93]have added dust and waste gases to the atmosphere.
[11:41.36]往大气中增添了很多尘埃和废气。
[11:43.79]It is time to learn how to protect our atmosphere,
[11:46.08]现在该 是我们应该学会怎样保护我们的大气
[11:48.36]the roof over the world of man.
[11:50.33]人类世界的屋顶的时候了。