I．词汇考查：分A、B两节（每小题1分，计10分）
A. 用括号内所给词的适当形式填空。
1. After so many ________ (year) practice, Li Na is a well-known tennis player.
2. I ________ (read) a novel last night when I heard knocks at the door.
3. The higher the mountain is, the ________ (thin) the air is.
