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
专升本
Look at a man walking down a street or road in’ the sunlight and you will see his shadow. If you watch two men walking in the su
Look at a man walking down a street or road in’ the sunlight and you will see his shadow. If you watch two men walking in the su
admin
2012-08-05
22
问题
Look at a man walking down a street or road in’ the sunlight and you will see his shadow. If you watch two men walking in the sunlight and carrying a six-fool pane(窗玻璃片) of glass between them, you will see each man six feet apart, but there will be no shadow of the pane of glass.
Shadows are easily explained since we know that light travels in a straight line. We also know that light waves pass through some bodies and not through others.
When light strikes a body and passes through it unchanged, we call such a body or material transparent. Most glass is such a material, especially window glass, and it is for this reason that we do not see the shadow of the window pane which the men are carrying. Do you know of any other transparent materials? The most common one, with which we are familiar, is air. Another is clear water.
On the other hand, some materials do not let light pass through them at all. They stop the light waves just as you would-catch a ball that was being thrown to someone standing between you. Such materials are called opaque. Men’ s bodies, like steel, rock, concrete or even cardboard, are opaque and do not permit the light to pass through. An opaque body casts a shadow.
Which of the following is not true?
选项
A、Light waves are beams of light.
B、Light waves can penetrate any materials except men’ s bodies.
C、Light waves can penetrate transparent materials.
D、Light waves can penetrate some materials.
答案
B
解析
文章第三段指出,光不能穿过某些材料如人的身体,钢铁,岩石等等。
转载请注明原文地址:https://kaotiyun.com/show/MIeC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
Haveyoueverbeenafraidtotalkbackwhenyouweretreatedunfairly?Haveyoueverboughtsomethingjustbecausethesalesman
Peopledonotanalyseeveryproblemtheymeet.Sometimestheytrytorememberasolutionfromthelasttimetheyhada【C1】______
Chinahasapopulationof1.3billion,______itthelargestcountryintheworldbypopulation.
—Carwontherace—Yes,butitsdrivercamecloseto______.
In,a(n)______lawwaspassedbytheUnitedNationstostoppeopleputtingwasteintosea.
AlthoughtheUnitedStatescherishesthetraditionthatitisanationofsmalltownsandwideopenspaces,onlyoneineveryei
Itispossiblethattheweatheroftheworldmaybechanging.Somescientistsimaginethatthiscouldevenmeanthebeginningof
Aroundtheworldmoreandmorepeoplearetakingpartindangeroussportsandactivities.Ofcourse,therehavealwaysbeenpeop
Americanhaslongbeenconsideredthelandofopportunitybythosefromothercountries.Americans,too,believethattheUnited
Theopeningbetweentherockswasverynarrow,buttheboysmanagedto______through.
随机试题
下列各句中“于”表被动的是()
类癌的特性为
小儿"稚阴稚阳"的含义是
下面哪一种方法不能作为照明的正常节电措施?(2003,112)
在我国现行财政体制下,下列税种中,属于中央与地方共享税的有( )。
在许多国家或地区,( )是社会工作中一项制度化的工作内容。
从1931年开始,日本帝国主义制造了一系列侵华事件,蓄意扩大对华侵略。“七七事变”发生在何时何地?()
中国革命胜利的原因有
一般情况下,当对关系R和S进行自然连接时,要求R和S含有一个或者多个共有的
A、Toknowhowmanyextramedicalstaffareneeded.B、Toclarifytheresponsibilityofgovernment.C、Tofindoutwhatpeoplereal
最新回复
(
0
)