some kinds of book中的book是不是一定要加s?

请问a book of cartoons 中的cartoon 为什么加s some book的“book”后面加s吗? What kind of book do you want?中的book用加s吗 some.book. The book store sells many different kinds of _____ (magazine which kind还是kinds of books还是book 5 kinds of book 还是 5 kind of books 还是 5 kinds of books呢 some kinds of 加 illness 还是 illnesses two different kinds of book 和 two kinds of different books 有 book做种类时可数吗 是 many kinds of book 还是books 英语中,book store,book要加s吗 They can do many kinds of work 中的work怎么不加s,不是有many kinds of