These are my rulers.Are those your siseters?(改为单数形式）Is that your sister?He is my grandfather.（改为一般疑问句并肯定回答）Is he your grandfather?Yes, he is.That is is friennd.(改为否定句）That isn't his friend.He's my frend.(改为一般问句）Is he your friend?Tose are my shoes。（改为单数句）That is my shoe.She's my cousin's mother.(改为同义句）She's my aunt.Guo ingjing is his sister。（改为否定句Guo Jingjing isn't his sister.怎么没完没了的追问啊？！请采纳之后另问，尊重他人劳动成果，是一种美德。