请英文高手帮帮忙（6）In many stories on TV and in science-fiction book

请英文高手帮帮忙（6）
In many stories on TV and in science-fiction books,men travel to faraway stars.They have quick,easy journeys.But so far,men have been able to reach only the earth’s own moon.
Suppose a man wanted to reach a distant star.Even if he traveled his whole life,he would have to move faster than the speed of the light.Nothing can move that fast except light itself.
Strange things happen to an object when it moves rapidly.The object weighs more.An object moving at 86 percent of the speed of light is twice as heavy as it is at rest.A stick appears shorter.A clock runs more slowly.A man would not age so fast as he would on the earth.
Light travels more than 186,000 miles a second,or about 11 million miles a minute.In one year,light travels six trillion miles.That great distance is called a light-year.It is used to measure distance in space.
The star closest to our sun is Alpha Centauri.It is more than four light-years away.If one traveled at the speed of light,he could make a round trip to Alpha Centauri in nine years.But,even at that speed,he could not reach Alcaid (北斗星) in the handle of the Big Dipper.A one-way journey to Alcaid would take almost 200 years.
6.In this passage the words “closest to our sun” means the star--------
a) the earth we live on
b) Alpha Centauri
c) The Big Dipper
d) The moon
7.A one-way journey to Alcaid would take--------.
a) about nine years
b) less than four years
c) almost 200 years
d) less than 100 years
8.Why do we measure the distance in light-years instead of miles?
a) Units of light-years sound better.
b) Using light- years reduced the number of figures used
c) We used to measure distance in light-years long ago.
d) We do not make mistakes when we use light-years.
9.If a stone moved at the speed of light,it--------.
a) would weigh twice more than it is motionless
b) would weigh as much as it is on earth
c) would weigh less than it is on earth
d) would not have weight at all
10.This story is mainly about--------.
a) the distance between the sun and the other stars
b) the problems of traveling to faraway stars
c) what happens when we travel faster than the speed of light
d) the tool we use when we go to faraway stars