单词拼写（每小题1分，共10分）

小题1:The ______(平均) age of the students in the class is only fourteen.

小题2: He waved his cap to ______(吸引) the rescue workers, but in vain.

小题3: Press the red ______(按纽) in case you have any emergency.

小题4: Don’t be so ______(贪心); leave some food for the rest of us.

小题5: He publically ______(挑战) traditional beliefs and certainly met with wide disapproval.

小题6: One of the ______(打字员) was to blame for the serious mistake.

小题7:He devoted himself to helping ______(智力地) disabled children in their education.

小题8: His voice sounds strange. There is something wrong with his ______(喉咙).

小题9:______(扫视) at the title, and you can guess what the passage is about.

小题10:Our company aims at quality rather than ______(数量).

—It's 10 o'clock now. I must go.

—It's raining heavily outside. Don't leave ______ it stops. [ ]

A. since

B. until

C. when

D. because