is this your father?否定回答 that is his sister?复数句

is this your father?否定回答 that is his sister?复数句 is that your friend 改为复数句 is this his backpack作否定回答 Is this your sister?否定回答 This is his sister改为复数句 Is that his sister?变为复数句 is this your father的否定回答 IS this your sister?(改为复数句) Is this your sister的复数句? 变复数句1.This is my booy2.Is that his uncle3.Is she your friend this is his book that is your ruler 改成一般疑问句并作肯定否定回答 Is this your teacher ?回答,否定句 That is my picture（改为复数句） Is she your daughter?(作否定回答)