Unit 3 Is this your pencil?习题一、单项选择。 ( )1. Please come ________, Mike. A. in B. for C. up ( )2. Wang Bing, open _____ book, please! A. you B. your C. me ( )3. --Good afternoon, ________ --Good afternoon, Mr Wang. A. class B. please C. door ( )4.—What’s this? --It’s__...