This is a box.改为复数形式

This is a box.改为复数形式 this is a box改为复数 1.This is a box.(改为复数形式) this’s a boxs. 1.This is a box.(改为复数形式) this’s a boxs. This book is in that box.（改为复数形式） What is this? It is a box.复数形式 it is a box.(改为复数形式）帮忙啊! this is a book改为复数形式 This is a dress.改为复数形式 This is a cat.(改为复数形式) This is a pen.(改为复数形式) This is a box and that is a knife.改为复数形式〔怎么变的〕 That is a box 改为复数句子 This is a box and that is a knife （改为复数句） 把This is a box and that is a knife.改成复数形式 把This is a yellow coat改为复数形式 This is a bus.改为复数形式的句子 This is a pretty dress改为复数形式