把下面的句子变成肯定、否定、疑问句！急啊~~高手快来

This is my sister
This isn't my sister
This isn't my friend
Is this your friend
That is my brother.
That isn't my brother

1、this is your sister
this is not your sister
2、this is not your friend
is this your friend？

按照上述模式直接套进去就好啦！
你不会是初一的吧 小孩

兄弟，上课没认真听讲啊。很简单的。

靠，你上课在干什么？
This is my sister./This isn't my sister .
Is This your friend?/This isn't my friend.
That is my brother./That isn't my brother.
Is that your brother?/That isn't my brother.

this is your sister.
this isn't your sister.

This isn't my friend.
is this my friend?

that is your brother.
that isn't your brother.

That isn't my brother.
is that my brother?

This is my sister.
This isn't my sister.

This isn't my friend.
Is this your friend?

That is my brother.
That isn't