81、If I___to do the experiment, I would do it some other way.
B.should be going
82、I would not be home tonight___ you not___me a lift in your car.
B.if had, given
83、We___it without your help.
A.couldn't have done
C.could have done
D.could haven't done
84、___in the crash, he won't participate in the race.
A.His broken leg
B.His leg is broken
C.His leg having been broken
D.His leg being broken
85、So fast ___that it is difficult for us to imagine its speed.
C.does light travel
D.has light traveled
86、Is this film moving?Yes, it is___.
A.Rarely have I seen this before.
B.Rarely before have I seen this.
C.Rarely have I seen before this.
D.Rarely I have seen this before.
87、I suppose she is not serious,___ ?
88、I can only do it for you ___I'm paid in advance.
D.on condition that
89、Whatever is worth ___ at all is worth ___well.
A.doing, being done
C.being done, doing
D.being done, being done
90、You'll see to it ___everything is ready in time.