this is a book改为复数形式

this is a book改为复数形式 There is a book.改为复数形式 Is that a book改为复数形式 This is a book 改为复数句 This book is in that box.（改为复数形式） How much is this English book?(改为复数形式） This is an Enlish book.(改为复数形式) This is my book.(改为复数形式) There is a nice cat in the tree.(改为复数形式)Those are rulers.(改为单数形式) This is a dress.改为复数形式 This is a cat.(改为复数形式) This is a box.改为复数形式 This is a pen.(改为复数形式) This is my book.改为复数形式 There is a nice cat in the tree.改为复数形式 Those are rulers 单数形式 this is a chinese book改为复数句 改成复数形式．4.This is a book. Is this a book?的复数形式是什么?3Q Whose book is that?改为复数形式 That book is his?改为复数形式