Light travels at a speed which is about a million times faster than the speed of sound. You can get some idea of this difference by watching the start of a race. If you stand some distance(距离) away from the starter, you can see smoke from his gun before the sound reaches your ears.

This great speed of light produces some strange facts. Sunlight(太阳光) takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light rays left the moon 1.3 seconds before they reached you. The nearest star is so far away that the light that you can see from it tonight started to travel towards you four years ago at a speed of nearly 2 million km. per minute. In some cases, the light from one of tonight’s stars had started on its journey to you before you were born.

Thus, if we want to be honest, we can’t say, “The stars are shining tonight.” We have to say instead, “The stars look pretty. They were shining four years ago, but their light has only just reached the earth.”

1.Light speed is ______ sound speed.

A. as fast as                          

B. a million times slower than

C. about millions of times faster than     

D. about a million times faster than

2. If you stand 200 meters away from a man who is firing a gun to start a race, you will find out that ______.

A. you can hear the sound before you see the smoke

B. the sound does not travel as fast as light

C. the sound will reach you before the man fires

D. sound travels about a million times faster than light

3.Sunlight obviously(显然的) ______ than the light of the moon.

A. has to travel a greater distance          

B. moves less quickly

C. travels much more quickly            

D. is less powerful

4. The scientific way of saying "The stars are shining tonight" should be ______.

A. the stars have been shining all the time

B. the stars seen tonight will shine four years later

C. the stars were shining long ago but seen tonight

D. the starlight seen today could be seen four years ago

　　Thus, if we want to be honest, we can not say,“the stars are shining tonight.”We have to say,“The stars look pretty. They were shining four years ago but their light has only just reached the earth.”

　　阅读短文，选择最佳答案．

(1) The speed of light is ________ than the speed of sound.

A．a million times slower

B．about millions of times faster

C．about a million times faster

A．you can hear the gun before you see the smoke

B．sound doesn't travel as fast as light

C．the sound of gun will reach you before the man fires his gun

A．has to travel a greater distance

B．moves less quickly

C．is less powerful

(4) The scientific way of saying“the star are shining tonight”should be ________.

A．the stars have been shining all the time

B．the stars seen tonight will be shining four years later

C．the stars were shining long ago but are seen tonight

根据短文内容，用方框中所给词的适当形式填空，并用其正确形式填空，使短文完整，正确。（每个词只能用一次；共10分，每小题一分）

Light travels at a speed(速度) which is about a million times faster than that of sound .1.

     One second, light travels about 300000 kilometers, but sound travels only 340 2.     .  You can get some idea of this difference by 3.________ the start of a running match. If you stand far away from the starter(发令员), you can see smoke4.________ from his gun before the sound reaches your ears.

The  5.      speed of light produces some strange facts. The 6.     star is so far away that light which you can see from it tonight started to travel to you  four years  7.________ at a speed of nearly two million kilometers every minute. The light from some of tonight's started on8. ________ journey towards you even before you were born.

So, if we want to be honest(诚实), we can not say , " The stars are shining 9. ________tonight."  We have to say, " The stars look nice. They were 10._______ four years ago but their light has just reached our earth. "

根据短文内容，用方框中所给词的适当形式填空，并用其正确形式填空，使短文完整，正确。（每个词只能用一次；共10分，每小题一分）

Light travels at a speed(速度) which is about a million times faster than that of sound .【小题1】
    One second, light travels about 300000 kilometers, but sound travels only 340 【小题2】     .  You can get some idea of this difference by 【小题3】________ the start of a running match. If you stand far away from the starter(发令员), you can see smoke【小题4】________ from his gun before the sound reaches your ears.
The 【小题5】     speed of light produces some strange facts. The 【小题6】    star is so far away that light which you can see from it tonight started to travel to you  four years 【小题7】________ at a speed of nearly two million kilometers every minute. The light from some of tonight's started on【小题8】 ________ journey towards you even before you were born.
So, if we want to be honest(诚实), we can not say , " The stars are shining 【小题9】 ________tonight."  We have to say, " The stars look nice. They were 【小题10】_______ four years ago but their light has just reached our earth. "