（1）How long has life been on Earth？
A.For millions of years.
B.For billions of years.
C.For hundreds of years.
（2）Have they found life on other planets？
A.Yes，they have.
B.No，they haven't.
C.Maybe they have.
（3）What does the Earth go around？
A.The Moon.
B.The solar system.
C.The Sun.
（4）Why have the scientists sent lots of spacecraft into space？
A.Because they want to travel in space.
B.Because they want to know more about our space.
C.Because they want to be famous all over the world.
（5）How can people get to space？
A.Take the plane.
B.Take the space shuttle.
C.We can't get there.