1. When I came to the riverside, I found a boy __________(挣扎) in the water.    
2. At ________(高度) of four miles, the air becomes too thin to breathe.
3. She hopes to be a __________(音乐家) in the future.
4. The _______(战士)  was praised for rescuing the child from drowning.
5. People should wash ______(定期)to ensure personal health.
6. Miss Green lives on the _______(十二)floor. We'd better take the lift.
7. The_______(秘书) informed me of his arrival by telephone.
8. Is it convenient for you to spare some time? I'll go and see you next ________(星期四).  
9. The thief ________(承认) his crime when he was questioned by the police.
10. The voice on the phone sounds _________(熟悉) to me.