日日人人_亚洲美女在线视频_av手机在线播放_国产大片aaa_欧美中文日韩_午夜理伦三级

Light from the sun reaches us in 8.5 minutes.The sun is about 149,640,000 kilometers 36 the earth.Other stars are 37 away than the sun.Light from the nearest star reaches us in about four years.When you look at a star.it is very 38 .But in fact many of them are 39 than the sun.They look small only 40 they are much farther away than the sun. 查看更多

 

題目列表(包括答案和解析)

  Light travels at a speed which is about a million times faster than the speed of sound. In a second, light travels about 300,000km, but sound travels only 340m. You can get some ideas 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 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 reach 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 20 million km, per minute. In some cases, 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 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.

  閱讀短文,選擇最佳答案.

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

[  ]

Aa million times slower

Babout millions of times faster

Cabout a million times faster

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

[  ]

Ayou can hear the gun before you see the smoke

Bsound doesn't travel as fast as light

Cthe sound of gun will reach you before the man fires his gun

(3) Sunlight ________ to the earth than the light of the moon.

[  ]

Ahas to travel a greater distance

Bmoves less quickly

Cis less powerful

(4) The scientific way of sayingthe star are shining tonightshould be ________.

[  ]

Athe stars have been shining all the time

Bthe stars seen tonight will be shining four years later

Cthe stars were shining long ago but are seen tonight

(5) The light of the nearest star you see tonight has been ________ for four years.

[  ]

Aaway from the star

Bon the moon

Caway from the sun

查看答案和解析>>

閱讀理解

  Light travels at a speed (速度) which is about a million times faster than that of sound. In one second, light travels about 300,000 kilometers, but sound travels only 340 meters. You can get some idea of this difference by watching the start of a running match. If you stand quite far away from the starter (發令員), you can see smoke come from his gun before the sound reaches your ears.

  The fast speed of light produces some strange facts. Sunlight takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light rays (射線) left the moon 1. 3 seconds before they reached you. The nearest star is so far away that light which you can see from it tonight started to travel to you 4 years ago at a speed of nearly 2 million kilometers every minute. The light from some of tonight's started on its journey towards you even before you were born.

  So, if we want to be honest (誠實的), we can not say, “The stars are shining brightly tonight.” We have to say. “The stars look nice. They were shining four years ago but their light has just reached our earth.”

1.The best title of this passage is ________.

[  ]

A.Light Travels Faster Than Sound

B.Stars Are Far Away From Us

C.The Speed of Light

D.How Light Rays Travel

2.If you stand 200 meters away from a man who is lifting a gun to 

start a running match, you will find out ________.

[  ]

A.light travels a million times faster than sound

B.the smoke of the gun gets into your sight after the sound of the gun-shot

C.sound travels less fast than light

D.the sound of the gun reached you at the same time with the light of the smoke

3.Sunlight obviously (明顯的) ________ than the light of the moon.

[  ]

A.has to travel a greater distance (距離)

B.moves less quickly

C.travels much more quickly

D.is less powerful

4.The scientific way of saying ``The stars are shining brightly 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 which were shining long ago but are seen tonight

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

5.The light of the nearest star you see tonight has been ________ for years.

[  ]

A.on the earth
B.on the moon
C.away from the sun
D.away from itself

查看答案和解析>>

完形填空

通讀下面短文,掌握其大意,然后在所給的四個選項中,選出一個最佳答案。

   Light travels very fast. It moves  1  300,000 kilometres a  2    . Light  3    us from the moon in less than a second and a half. The moon is about 382,000 kilometres  4    .

   Light from the sun reaches us 8.5 minutes. The sun is about 149,640,000 kilometres from the earth.

   The other stars are farther away than the sun. Light from the nearest  5    reaches us in about four years. When you look at a star, you do not  6    its present condition(目前現狀). You see it as it  7    to be. Light from some stars  8    hundreds of years to reach us. We never see a star as it is  9    . We see it as it was long ago, perhaps (也許) hundreds or thousands of years ago.

   Astronomers(天文學家)watch stars  10    big telescopes (望遠鏡). With these telescopes astronomers can see stars and other things very far away.

                                                                                                                                                     

(1) A.on

Bat

Cwith

Dby

[  ]

(2) Aminute

Bhour

Csecond

Dday

[  ]

(3) Areaches

Bgets

Carrives

Dcomes

[  ]

(4) Ahigh

Bfar

Clong

Daway

[  ]

(5) Astar

Bmoon

Csun

Dearth

[  ]

(6) Alook at

Bsee

Ctouch

Dreach

[  ]

(7) Ause

Bused

Cis used

Dusing

[  ]

(8) Atakes

Btake

Cspends

Dspend

[  ]

(9) Abefore

Bafter

Cnow

Dfuture

[  ]

(10) Ain

Bthrough

Cinto

Donto

[  ]

查看答案和解析>>

主站蜘蛛池模板: 亚洲综合国产 | 欧洲国产伦久久久久久久 | aaa日本高清在线播放免费观看 | 在线a视频 | 久久亚洲国产精品 | 久久精品小视频 | 国产精品爱久久久久久久 | 国产99久久精品一区二区永久免费 | 久久精品网 | 午夜影院a| 免费av毛片 | 日韩日韩日韩日韩日韩日韩日韩 | 国产欧美日韩一区二区三区 | 成年免费a级毛片 | 日韩久久精品电影 | 亚洲一区不卡 | 亚洲精品成人av | 久久精品视频偷拍 | 2018狠狠干 | 91中文字幕在线 | 亚洲成人在线免费 | www.操.com | 日韩精品视频免费在线观看 | 午夜精品久久久久久久久久久久久 | 欧美日韩成人免费 | 久久精品欧美一区二区三区不卡 | 一级毛片免费看 | 国产激情视频在线观看 | 露娜同人18av黄漫网站 | 国产探花在线精品一区二区 | 97视频观看 | 欧美一级在线播放 | 国产成人免费av一区二区午夜 | 欧美一级免费观看 | 午夜精品久久久久99蜜 | 久久久91| 国产精品美女久久久久久免费 | 超级乱淫片国语对白免费视频 | 日韩av一区二区三区在线观看 | 日韩在线观看 | 日韩色av |