And they're looking for ()mother ,too.空里应填their还是theirs?为什么?求解!

And they're looking for ()mother ,too.空里应填their还是theirs?为什么?求解!

their
形容词性物主代词后面才可以接名词.
名词性物主代词后不能接名词.

their
这里用形容词性的物主代词即可

their这是名词前，作定语的。
my father
your teacher
主语表语才用theirs
theirs=their + 名词
如：
The book is mine=The book is my book.

their就是他们的。