This isn't my MP4 player.__ is at my uncle's.填MINE为什么AT怎么解释

This isn't my MP4 player.__ is at my uncle's. This isn't my MP4 player.__ is at my uncle's.填MINE为什么 This isn't my MP4 player.__ is at my uncle's.填MINE为什么AT怎么解释 my MP4 player isn't in my bagMy MP4 player isn't in my bag.Where _____ I have put it?[ ]A.can B.must C.should D.would 为什么选A? This isn't my brother 变复数形式 this isn t my grandparent改为复数形式 This isn’t my bike.（）I is over there This isn't my shirt.It's_________(you) This isn't my notebook.变为一般疑问句 this just isn't My MP4 player isn't in my bag.Where___I have put it?A.can B.must C.should D.would 请顺便解释下原因 My MP4 player isn't in my bag .Where____I have put it My MP4 player isn't in my bag.Where___I have put it?A.can B.must C.should D.would 请问答案为何是 A 这与 have put 这个完成时态 This isn't my pencil box.-----is red.A.My B.Mine C.Her D.his This isn't my bag.M__ is a yellow one.那个M__ 是要填My 还是Mine? my uncle has a brother but this man isn't my unclehe is... This isn't my trumpet. ______(my) is next to the chair.适当形式、、 this is not my ... 和 it isn‘t my ... 有什么区别么? It isn't my pencilcase,but this is my backpack是什么意思?