题目内容
2．Light travels at a speed which is about a million times faster than the speed of sound．In one second，light travels about 300，000km，but sound travels only 344m．You can get some idea of this difference by watching the start of a race．If you stand some distance away from the starter，you can see smoke come from his gun before the sound reaches your ears．This great speed of light produces some strange facts．Sunlight takes about 8minutes to reach us．If you look at the light of the moon tonight，remember that the light rays（光线）left the moon 1.3seconds before they reached you．The nearest star is so far away that the light which you can see from it tonight started to travel towards you four years ago at a speed of nearly 2million km per minute．In some cases（在某种情况下）the light from one of tonight's stars started on its journey to you before you were born．Thus，if we want to be honest，we cannot say"The stars are shinning tonight．"We have to say，"The stars look pretty．They were shining four years ago but their light has only just reached Earth．"
41．If you stand 200meters away from a man who is firing a gun to start a race，you will find out thatB．
A．you can hear the gun before you see the smoke．
B．sound does not travel as fast as light．
C．the sound of the gun will reach you before the man fires his gun．
D．sound travels about a million times faster than light．
42．Sunlight clearlyA 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
43．What does"it"in the second paragraph refer to？C
A．moon light
B．light rays
C．the nearest star
D．the moon
44．The scientific way of saying"The stars are shining tonight"should beC．
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．
D．the starlight seen today could be seen four years ago．
45．The light of the nearest star you see tonight has beenD for years．
A．on the earth
B．on the moon
C．away from the sun
D．away from the star．
分析 这篇短文中作者主要介绍了光的传播速度要远远高于声的传播．文章又向我们描述了一种奇怪的自然现象，引起了人们的思考．
解答 BACCD
41 B 细节理解题．根据短文第一段最后一句话If you stand some distance（距离） away from the starter，you can see smoke from his gun before the sound reaches your ears．可知，看到烟雾要比听到声音早，即声音和光传播的并不是一样快的，其他三项表述错误；故选B．
42 A 推理判断题．根据短文第二段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．两句可知，太阳光传播的距离要远远大于月光；故选A．
43 C 细节理解题．根据文章The nearest star is so far away that the light which you can see from it tonight started to travel towards you four years ago at a speed of nearly 2million km per minute．可知最近的恒星是如此远，但你今晚看见的光却是它四年前以每分钟200万千米的速度传来的，故选C．
44 C 推理判断题．根据短文最后一句话"The stars look pretty．They were shining four years ago，but their light has only just reached the earth．"可知我们今晚看到的星光是四年前就已经发射出来了，只是我们现在才看到；与C项描述相吻合；故选C．
75 D 细节理解题．根据文章The nearest star is so far away that the light which you can see from it tonight started to travel towards you four years ago at a speed of nearly 2million km per minute．可知最近的恒星的光波早在4年前就已经离开奔向你了，故选D．
点评 考察学生的细节理解和推理判断能力，做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确的选择．在做推理判断题不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．
