Unit 9 单元测试题Written test part (共95分). 单项选择(每小题1分, 共15分)从A、B、C、D四个选项中选择可以填入空白处的最佳答案。( )21. The party is _ 5:00 _ Tuesday afternoon. A. at; at B. at; on C. on; at D. on; on ( )22. You cant leave _ your parents come.A. because B. until C. if D. when ( )23. Lets go to the _ tonight. Lang Lang will play the piano.A. cinema B. mountain C. concert D