It was _____back home after the experiments.
| A.not until midnight did he go | B.until midnight that he didn’t go | 
| C.not until midnight that he went | D.until midnight when he didn’t go | 
He had no sooner finished his speech________ the students started cheering.(2011·辽宁)
| A.since | B.as | 
| C.when | D.than | 
He smiled politely ________ Mary apologized for her drunken friends.(2012·山东)
| A.as | B.if | C.unless | D.though | 
________ we have enough evidence,we can't win the case.
| A.Once | B.As long as | C.Unless | D.Since | 
He is so busy.He cannot afford enough time with his son________he wants to.
| A.even if | B.as if | C.because | D.before | 
I have heard a lot of good things about you ________ I came back from abroad.
| A.since | B.until | C.before | D.when |