Fill in each blank with ONE suitable preposition given

       I.            Fill in each blank with ONE suitable preposition given: in, at, on, since, for, to

1.      Paper money has been used  ........................over a thousand year.

2.      The bus stopped........................ the gas station to get some more fuel.

3.      He will be in Thailand........................June.

4.      What do you often do ........................ Sunday?

5.      They have studied English  ........................2002.

6.      They walked ........................half an hour to reach the waterfall.

7.      We had an appointment........................5 o’clock.

8.      Her birthday is ........................ December.

9.      They have studied English  ........................2004.

10. I look forward ........................hearing from you.

11. We enjoy watching stars........................night.

12. Do you have English classes ........................ Monday and Friday?