-----book on the desk is ----useful one答案是：The book on the desk is useful one.为什么useful前面不能用an或the?

the book on the on the Avenue des Champs Elysees还是in the Avenue des Champs Elysees the book on the right _____ ____ the book? The book is on the table. the english book is on the shelfthe book on the shelf is an english book in the book/on the book这两个哪个对? an artical on the book 还是 in the book Put the book on the chair the book is on the desk. THE BOOK ON THE BOOKSHELF怎么样 The book is on the desk. The book is on the swing I like the book better .the book is on the left.I like the book ( ) ( )( ) better the Salle des His book is on the desk.(划线提问His book on the book,in the book,from the book这三者是什么区别 the book on the desk 和the book is on the desk 哪句是对的·? leave the book lying on the desk还是leave the book lain on the desk