these aren't their brothers改为单数句 jack is my brother's good friend.改为一般疑问句,并做肯定回答is this your sister 改为复数句

问题描述:

these aren't their brothers改为单数句 jack is my brother's good friend.改为一般疑问句,并做肯定回答
is this your sister 改为复数句

This is not his bother.(此处不可用isn't哦)
Is Jack your bother's good friend? -Yes,he is.
Are these your sisters?

This is their brother.
Is jack your brother's good friend?Yes it is

This is't his brother.
Is Jack your brother's good friend? -Yes,he is.
Are these your sisters?

He is not his brothers;
Is jack your brother's good friend? yes he is;
Are these your sisiters?

This is't his bother.
Is Jack your bother's good friend?-Yes,he is.
Are these your sisters?
英语要好好学啊……