4.时间状语从句,条件句中,从句中(常含有till , once , as soon as ,
when ,
while , before , after , so long as , by the time , if , in case ,
unless ,
even if , whether , the moment , the minute )
Eg. As
soon as I get there, I will deal with this matter.
Whether he
is happy is an important thing to her.