按要求完成下列各题（每小题1分，共5分）
These are my brothers. (改为单数句)
_________ __________ my brother.
My name is Helen. (同义句)
                   Helen.
That is my sister. (改为复数句)
_________ _________ my sisters.
— Is he your uncle? (作否定回答)
— ______, ______ isn’t.
These are my cousins. (改为一般疑问句)
________  ________  your cousins?