1. That activity book is his.（对his划线）
否定句：That activity book isn't his.
一般疑问句：Is that activity book his?
回答：Yes, it is. No, it isn't.
特殊疑问句：Whose is that activity book?
2. It's the girl'stextbook.（对girl's划线）
否定句：It isn't the girl's textbook.
一般疑问句：Is it the girl's textbook?
回答：Yes, it is. No, it isn't.
特殊疑问句：Whose textbook is it?
3. That glue is Dick and Tom's(对Dick and Tom's划线）
否定句：That glue isn't Dick and Tom's.
一般疑问句：Is that glue Dick and Tom's?
回答：Yes, it is. No, it isn't.
特殊疑问句：Whose is that glue?
注意：此题是Dick and Tom's,所以变否定句时,不能把and改成or；
如果是Dick's and Tom's的话,则变否定句时,要改成Dick's or Tom's.