M: Hello, Tim．How are you?
T: 36      What about you, Mary?
M: I’m OK, thanks．Do you like some tea?
T: 37      Do you have any orange juice（果汁）?
M: Of course．38     
T: Thanks very much．Is this the photo of your family?
M: 39      
T: And is the boy with a basketball your brother?
M: 40     

1M: Hello, Tim．How are you?

T: 36       What about you, Mary?

M: I’m OK, thanks．Do you like some tea?

T: 37       Do you have any orange juice（果汁）?

M: Of course．38     

T: Thanks very much．Is this the photo of your family?

M: 39      

T: And is the boy with a basketball your brother?

M: 40     

Scientists think that there has been life for__31_ of years. However we haven’t found life on other planets _32_ . The earth is a planet and it _33__ around the sun. Seven other planets also go _34_ the sun. The sun and its planets are __35  the solar system. The solar system is a small part of our galaxy.

Scientists __36_ lots of spacecraft to look at other planets in the solar system, and some spacecraft have gone __37_ the solar system. However, no one __38_ any life in space yet.

But why has no one from other planets sent us a message ? Have they tried to send _39_ to us ? _40_so many stars in the universe, are we alone, or is there life out there in space ? We don’t know.