19.He can’t have gone out,　　 　the light is still on.

A.because　　　　 B.since　　　　 C.as　　　　　 D.for

18.　　 　the day went on,the weather got worse.

A.With　　 　　　　　　B.Since　　　　　　　 C.As　　　　　　　 D.While

17.　　 　the baby fell asleep 　　　the room.

A.After；did the mother leave　　　　　　 B.Not until；did the mother leave

C.Not until；the mother left　　　　　　 D.Soon after；the mother had left

16.I’ll start early,　　 　it may be dark.

A.however　　　　　　 B.whether　　　　　 C.if　　　　　 　D.though

15.　　 　that none of us could follow him.

A.He spoke very fast　 B.So fast he spoke　 C.Too fast he spoke　　 D.So fast did he speak

14.You’d better do 　　　you are required.

A.like　　　　 B.which　　 　　　C.that　　　　 D.as

13.　 　we have come,let’s stay and enjoy it.

A.For　　　 B.As　　　　　 C.Because　　　　 D.Since

12.　　 　many times，but he still couldn’t understand it.

A.Having been told　　 B. Though had been told　 C.He was told　　 D.Having told

11.　　 　had the bell rung 　　　the students took their seats.

A.Hardly；when　　 B.No sooner；when　 C.Hardly；than　　 D.No sooner；then

10.These planes can fly 　　　than the old ones.

A.as fast three times　 B.three times as fast　 C.three times fast　 D.three times faster