用适当的介词填空。
1. The black shirt is _____ sale for eight dollars.
2. They have shorts_____ all colors.
3. What does your father do _____ Fridays?
4. Mona often goes to see movies_____ her sisters on weekends.
5. His cousin is good_____her friends.
6. Her sister usually goes to school_____seven-thirty.
7. These old people love to listen _____ Mrs Black.
8. Please write_____me soon.
9. Does your mother want to know_____my family?
10. The girl usually plays ping-pong_____two hours after school.