27. Who is the _________(先驱) in the field?　

26. That flying school graduates a hundred _________(飞行员) per year.

25.　 I was so tired that I fell asleep the moment my head touched the _______(枕头).

24. ---Last week the Smiths had several __________(野餐).

23. There is not enough room left for two such _________(钢琴).

22. Can you tell me some famous ___________(物理学家).

21. Tom is _________(身体) strong, but mentally weak.

20. Our _________(物理) teacher is full of energy.

19. Keep still while I take __________(照片) of you.

18. At last we ________(说服) father into giving up smoking.