Scientists think that there is life on the Earth for millions of years.However,we can\’t find life on other planets.
The Earth is a planet and it goes around the Sun.Seven other planets also go around the Sun.None of them has an environment with air,so people and things cannot grow.The Sun and its planets are called the solar system （太阳系）.The solar system is a small part of our galaxy（星系）.
Scientists find many other galaxies in the universe.But they are a long way away because their light has travelled for many years to reach us.It is hard to understand how large the universe is.
So far,scientists have sent lots of spaceships to look at other planets in our solar system,and some spaceships have gone beyond the solar system.However,no one can find any life on other planets yet.
（1）How many planets go around the Sun? ______
A.Seven.
B.Eight.
C.Nine.
D.Ten.
（2）What have scientists sent in order to look at other planets in our solar system? ______
A.E- mails.
B.Planes.
C.Spaceships.
D.Letters.
（3）Who can find life on other planets? ______
A.None.
B.A scientist.
C.A traveller.
D.A teacher.
（4）Which of the following is TRUE? ______
A.All the planets have an environment with air.
B.The solar system includes （包括） the Sun and its planets.
C.There is only one galaxy in the universe.
D.The Sun goes around the Earth.
（5）What\’s the best title of this passage? ______
A.The Earth
B.Our solar system
C.The stars at night
D.Something strange in the sky