裂解气脱水的目的是（）。
A.防止结冰
B.防止形成水合物
C.防止水合反应
D.保证产品纯度
参考答案：A, B, D
用所给词的适当形式填空
1. The boy hurried forward ____ ( see) the world-famous oil painting because he had been looking
forward to _____ (see)it for a long time.
2. The day I had been looking forward to ____ (come).
3. I used to ____ (get) up late, but now I' m used to ____ (get) up early.
天可汗
