why does man want to go to other planets in the solar system ?just for fun? True, there is adventure in space travel . but a trip to other planet 
 would also be practical .for example ,space stations could be built that would give us valuable information about the weather.
in space stations moving around the earth ,man could live and study the could formations on its surface . these formations could tell us what weather to expect in any part of the world any time . such information would be very useful to pilots, to ship captains and even to farmers who must set dates for planting and harvesting.

II

1. He said to her, "You are my friend"

=>he told her that she was his friend

2. Johnny said to his mother, " I don't know how to do this exercise"

=>Johnny told his mother that he didn't know how to do that exercise

3. "Don't come back before one o'clock", advised my brother.

=>My brother advised me no to come back before one o'clock

4. "Cook it in butter", Mrs Brown said to her daughter.

=>Mrs Brown told her daughter to cook it in butter

5. The pupil said, "Teacher, give us better marks,please."

=>The pupil told teacher to give them better marks

6. My friend said "Are you going to leave tomorrow?"

=>My friend asked me if i was going to leave the next day

III. 1. in, 2. there, 3. trip, 4. valuable, 5. practical, 6. moving, 7. its, 8.  travel, 9.such, 10. who.

IV. 

1. He told her she was his friend.
2. Johnny told his mother he didn't know how to do that exercise.
3. My brother advised me not to come back before one o'clock.
4. Mrs Brown told her daughter to cook it in butter.
5. The pupils told their teacher to give them better mark.

6. My friend asked me if I was going to leave the next day.