1. There are two classes _____ Wednesday afternoon. (99南京)　 A. at 　B. in 　C. on 　D. to

20. The children are waiting _______ the gate _______ their mother.

19. The teacher is writing ______ red ink _______ a piece of paper.

18. It’s cold and the temperature is ________ zero during the night.

17. Thanks ______ your help. I finished the work before dark.

16. Please meet your uncle ______ noon ______ Saturday.

15. You must learn these words _______ heart, and answer my questions ____ English.

14. The teacher told us the moon travels ________ the earth.

13. Don’t read _______ the sun. It’s bad ________ your eyes.

12. It’s very kind _______ you to help me _______ my maths.