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 my book（改为复数句） this is my book帮我改为复数句 IS this his book?改为复数句 This is my pencil.改为同义句 This is my book,and that is his book(改为复数句） This is a book 改为复数句 this is a book改为复数形式 this is my book.改为一般疑问句. This is my book改为同义句 This is my sister.改为复数形式、 This is my brother.(改为复数） This is my friend 改为复数形式 This is my cousin.改为复数形式. this is my teacher.改为复数句子 This is my cousin.(改为复数句) 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) That is my parent 改为复数句 Are those your grandparents 作肯定回答 This is her friend 变为否定句That is your 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）