how old （is） your sister 为什么是 is 给个理由快啊,真的快,不需要打几个字的

How old is your mother? How old is your mather How old is your father? How old is your father? How old is your g_______? how,is,your,old,friend How old is your father? How old is your son old sister how your is (连词成句） how old is your sister?she is 11 years old. 英语翻译How old is your cousin?不算 How old is your mother怎么回答 How old is your mother?回答句子 how,sister,old,is,your组句 How old is your brother 同义句 How old is your brother?回答 how old is your father怎么回答 连成一句话：old,is,aunt,how,your(?)