1．地点状语从句：地点状语从句多由where 或wherever 引起：
winters were very long wherehe lived．
i'm standing where the brook and the river meet.
he left the camera where it was.
wherever he went, he took her with him.
sleep wherever you like．
you can sit any where you like．
everywhere i go, i find the same thing.
2．原因状语从句：原因状语从句多由because, as, since, seeing ( that ), considering that 等连词引起：
you only do it becauseyou have to.