首页
登录
职称英语
[originaltext] If you’re driving on a highway, the only thing keeping you fr
[originaltext] If you’re driving on a highway, the only thing keeping you fr
游客
2024-05-06
26
管理
问题
If you’re driving on a highway, the only thing keeping you from going faster than the speed limit is your sense of civic duty, or perhaps that police car up ahead. There’s one speed limit, however, that most scientists agree nothing will ever break. That’s the speed of light: 186, 280 miles per second. As it trav-els through deep space, light moves at exactly this speed, no more and no less. The speed of light is so reliable, we even use it to measure distances between the stars. If it takes starlight fifty years to reach us, we say that this star is fifty light years away. You might be surprised to learn, however, that light itself does not always travel at the speed of light. Our highways generally have a higher speed limit, but once you enter a city or residential street, the speed limit lowers. Likewise, light travels at its maximum speed through a vacuum but it slows down when it enters air, water, or some other medium. Through air, light moves a little slower: forty miles per second less than its maximum speed. Through glass, light moves almost eighty thousand miles per second slower.Light moves more than a hundred thousand miles per second slower through a diamond less than half its speed in a vacuum. Light moves so quickly anyway, do we ever notice this change in speed? Actually, we do. When light slows down it also bends slightly. If light always moved at its maximum speed, none of our telescopes, eyeglasses or even our eyes themselves would ever work.
1.What does the passage mainly talk about?
2.Why do we use light speed to measure distances between the stars?
3.What will happen if light moves through a diamond?
4.What would happen if light always moved at its maximum speed?
选项
A、The light will bend a lot.
B、The speed limit will be lower.
C、The speed of light will not change.
D、The speed of light will be lower.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3586438.html
相关试题推荐
【B1】[br]【B11】[originaltext]JazzcapturestheessenceofAmerica.Forgo
【B1】[br]【B10】[originaltext]JazzcapturestheessenceofAmerica.Forgo
【B1】[br]【B8】[originaltext]JazzcapturestheessenceofAmerica.Forgoo
【B1】[br]【B3】[originaltext]JazzcapturestheessenceofAmerica.Forgoo
[originaltext]Onewaythatscientistslearnaboutmanisbyanimals,sucha
[originaltext]Onewaythatscientistslearnaboutmanisbyanimals,sucha
[originaltext]Millionsofwordshavebeenwrittenaboutyoungpeopleinthe
[originaltext]Millionsofwordshavebeenwrittenaboutyoungpeopleinthe
[originaltext]Millionsofwordshavebeenwrittenaboutyoungpeopleinthe
[originaltext]Amsterdam,theNetherland’scapital,isoneoftheworld’sbe
随机试题
Politician:Nobodycandenythathomelessnessisaproblemyetthereseemstobe
ThelongestriverinBritainis______.A、theSevernRiverB、theThamesRiverC、th
A、Graduatestudents.B、Undergraduatestudents.C、Professors.D、Libraryemployees
某建设单位为了提高公司整体运行效率,拟进行XX服务平台的升级改造工作,通过公开招
右边表格中的内容反映的是()。 A.管仲改革 B.商鞅变法 C.孝文
下列关于住房公积金的使用,说法正确的有()。A.住房公积金的使用包括职工个人
Thechangeinthatvillagewasmiraculou
(共用题干)患儿女,6岁。误食灭鼠药中毒,紧急送入医院救治。 社区护士关于
某工程建设项目施工承包合同中有关工程价款及其支付约定如下:(1)签约合同价:82
患者,女,22岁,因右下第三磨牙低位埋伏阻生,要求拔除。 拔牙后第3天,拔牙区
最新回复
(
0
)