The earliest age at which a girl is able to bear childiren这是个什么句型，能否再给举级个例子谢谢！

这是个状语从句。原句的语序应该是at that age a girl is able to bear children .
例句有两个比较经典的
I won't forget the day when I gave birth to my son .
我永远不会忘记生我儿子的那天
I won't forget the place where I gave birth to my son
我永远也不会忘记生我儿子的那个地方。
（我们老师的经典句子）

这是状语从句

The biggest place where you can find a place to PP