this is my knife改复数句

this is my knife改复数句 That is my knife.改复数句怎么做? This knife is his.怎么改复数形式的句子? There is a knife on the desk.改复数句 This is my shirt.改为复数句怎么改 this is knife in the box（变复数句 My knife is over there.(改为复数句） 英语句子单数改复数!1、it's a knife.2、this is my book.3、what's this?4、w this is my cousin 改复数句子 He has a knife.改复数句 This dress is mine改复数句 Is this your knife 改为复数句子