英语问题将句子合成定语从句This is our English teacher.He loves us allYest

his is our English teacher who loves us all.(指人用who)
Yesterday I helped an old man who lost his way.(指人用who)
Is the cat which/that is jumping about yours?(指物用that/which )
This is the only thing that we can do now.(这一句只能用that不能用which,因为前面有the only修饰thing.

This is our English teacher who loves us all.
Yesterday I helped an old man who lost his way.
Is the cat jumping out yours?
This is the only thing that we can do now.

sad