阅读理解
A long time ago people thought that the Sun went round the Earth. In
some countries people even said that the Sun was a god(神). They thought the god drove across the sky each day on a golden horse. Now we know the Earth goes round the Sun. It takes the Earth a year to go all way round the Sun.
Today man even know how far it is for the Earth to go round the Sun. They
tell us that the Earth travels over a thousand miles a minute on its journey
round the Sun.
The Sun is really a star. It is much bigger than the Earth and it is very hot. Some people have been to the moon but we know that no one can ever go to
the Sun. It is far too hot for people to live anywhere near it. The Sun is three hundred thousand times(倍)heavier than the Earth and more than 1 million
times larger.
1. A long time ago, people said the Sun was _____.
A. a golden horse of god
B. a god on a golden horse
C. a god with golden dress
D. a god and a golden horse
2. People can never live anywhere near the sun because it is _____.
A. too hot
B. too far
C. too small
D. too heavier
3. The Earth travels over _____ miles an hour.
A. 1, 000
B. 100, 000
C. 6, 000, 000
D. 60, 000
4. One year is _____.
A. the time for the Earth to turn round.
B. the time the Earth travels one thousand miles.
C. the time the Earth goes round the Sun one circle(圈,周).
D. the journey of the Earth.
5. Which of the following is TRUE? _____
A. The moon is the planet of the Sun.
B. One day man can land on the Sun.
C. The Sun is a star like other stars.
D. The moon is the nearest star to us in space.
m，因此金属的逸出功W= J，现在用频率7.5
1014Hz的光照射钠产生的光电子的最大初动能是 J. （普朗克常量h=6.631