变复数Whose knife is this?It‘s Peter’s.——————————————————————

Whose knife is this?(改成复数) This is a knife.怎样变复数. Is this her knife变复数 whose knife is this?将句子变成复数 whose is that book（变复数） this is knife in the box（变复数句 “knife”怎样变复数形式? knife的复数怎么变 变复数Whose knife is this?It‘s Peter’s.—————————————————————— fork and knife可以变复数吗 She has a knife.变复数句 knife变复数后knives怎么发音? This is a box and that is a knife.改为复数形式〔怎么变的〕 This is a knife 改为复数 Is this your knife 改为复数句子 this is my knife改复数句 knife复数 is怎么变复数