问题 选择题
2002年诺贝尔物理学奖中的一项,是奖励美国科学家贾科尼和日本科学家小柴晶俊发现了宇宙X射线源.X射线是一种高频电磁波,若X射线在真空中的波长为λ,以h表示普朗克常量,c表示真空的光速,以E和m分别表示X射线每个光子的能量和质量,则(  )

A.E=,m=0

B.E=,m=

C.E=,m=0

D.E=,m=

答案

答案:D

阅读理解

阅读理解

     For many people in the US,sports are not just for fun.They're almost a "religion".Thousands of sports fans buy expensive tickets to watch their favorite teams and athletes play in person.Other fans watch the

games at home,sticking to their TV sets,never missing a game.Many a wife becomes a "sports widow"

during her husband's favorite season.Americans' devotion to sports has created a new class of wealthy

people:professional athletes.Sports stars often receive milliondollar salaries.Some even make big money by appearing in advertisements for soft drinks,shoes and almost everything.

     Sports are an important part of American culture.Throughout their school life,Americans learn to play

many sports.Many students try out for the school teams.Athletic events at universities attract scores of fans and benefit the whole community.Many people also enjoy noncompetitive activities,like hiking,cycling,

horseback riding,camping or hunting.

     Many sports were imported from other countries.Europeans brought tennis,golf,bowling and boxing to America.Football and baseball came from other Old World games.Only basketball has a truly American origin.Americans export sports fever as well.Satellites broadcast games to sports fans around the globe.NBA is a good example.The names of American superstars like basketball great Michael Jordan have become

household words all over the world.

1. Many a wife becomes a "sports widow" in the US probably because________.

A. they are serious in religion

B. they are devoted to sports

C. their husbands stick to sports

D. their husbands are missing

2. Which of the following is NOT true according to the passage?

A. The US sports stars can earn a large sum of money via the media.

B. American students go in for various sports and athletic events.

C. Lots of American people take part in noncompetitive activities.

D. American people like to exchange different sports from each other.

3. We can infer from the passage that________.

A. all the Americans are sports fans

B. sports culture influences the world

C. most Americans like competition

D. America has invented many sports

4. The writer mainly intends to tell us________.

A. how important sports are in America

B. where sports can help to make money

C. why sports are so popular in America

D. what affect Americans' everyday life

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