10.hardly…when 表时间，“（刚）一…就” Hardly I entered the gate when the bell rang.
11.if “假如”，引导条件状语从句 What should I do net if the rain doesn’t stop?
“是否”，引导宾语从句 I don’t know if he comes back or not.
12.In case 表目的，“以防，以免” You should be more careful in case there is a fire.
13.In order that 表目的，“为了，以便” We study hard in order that we can pass the exam.
14.no matter +疑问词 表让步，“无论，不管”
No matter what you do, you should try your best.
15.no sooner…than 表时间，“刚一…就…”
No sooner had I come home than it began to rain.
16.now that 表原因，“既然，因为，由于”
Now that you are on duty,you should clean the classroom.
17.once 表时间，“一旦…” Once you promise , you should do it.
三、其他
1.since 表时间，“自从…以来” He has been in this company since he left school.
表原因，“既然，由于” Since the job is dangerous, let’s do it more carefully.