This a book is good 怎么改错

This a book is good 怎么改错 改错This is a expensive book 改错题：This is a my book. 改错i think this is a good book.i don't think it 改错：is this book your? This is a book for my father.英语改错.thank! 安.请问,This is a good book.（改为同义句） This is a ____ book. This is a book this is his the best book改错 改错Who's book is this?（） 改错 Who's book is this? there is a book in the desk 怎么改错