is this your watoh 变复数 This is my mother.对my mother提问

is this your watoh 变复数 This is my mother.对my mother提问 is this your ball?(变复数） Is this your backpack?变复数要怎么变啊! Is this your pencil?Yes ,it is.变复数 this is your pencil sharpener.变复数________your___________ Is this your computer?变陈述句——is——computer 变复数形式.1、This is his case.2.this is her hat.3.this isn,t my passport.4.is this your coat ? is this your skirt this is your Maybe this is your Is this your uncle? this is your aunt. is this your business Is this your schoolbag? Is this your (空格) Is this your schoolbag? this is your pencil Is this your cake.