I could feel my heart beating violently ______ I went on the stage to sing a song.
| A.for the first time | B.by the time | C.every time | D.from time to time | 
The driver was at ____ loss when _____ word came that he was forbidden to drive for speeding.
| A.a, the | B./, / | C.the, the | D.a, / | 
—Did you enjoy yourself at the party?
  —Yes.I've never been to ______ one before.
| A.a more excited | B.the more excited | C.a more exciting | D.the most exciting | 
Fitness is important in sport, but of at least _____ importance are skills.
| A.fair | B.reasonable | C.equal | D.proper | 
It's usually warm in my hometown in March, but it ___ be rather cold sometimes.
| A.must | B.can | C.should | D.would | 
I have _____ all my papers but I still can't find my notes.
| A.looked through | B.looked for | C.looked after | D.looked out |