Is this book is written by Bill Gates 到底是用is还是was 我知道是被动语态

Whose book is this? This is a book whose is this book? This book is yours Lily,is this book()? this is ( ) book. Is this a book? Yes,this is. This is my book.This book is mine造句 this is my book. this book is mine 区别是什么? This is s book.(a book提问) This book is ()(real) interesting 改错：is this book your? is ,an,book,english,this Whose is this book ?对吗? This book is about me. This is () useful story book.. is this her book?回答 This is ( ) book.your|yours