外研版英语(刘兆义主编)四年级上册 Unit 2 In the classroom 课时练习一、单选题1.Open ______ books, please!( ) A. you B. your C. on2.Put it _____ the teacher's desk. ( ) A. in B. you C. your3.- What's this? ( )- It's a ________. A. cat B. you C. under4.What _______ this? ( ) A...