21.He replied (　　　 )the teacher correctly and quickly.

20.(　　　 )present,he is working in a big company in USA.

19.We must concentrate all our energy and time (　　　 )this task.

18.Don’t stay (　 　　　)before the final exam .

17.Every morning he goes to school on foot (　　　 )(　　　 )by bike.

16.My parents are proud (　　　 )my swimming skills.

15.His parents take pride (　　　 )him,because he will go to Beijing University for further study.

14.(　　　 )his surprise, he passed the exam after all.

13. He fell ill seriously and was terrified (　　　 )death.

12. The teachers are very patient (　　　 )their students.