煤气的冷却主要靠氨水（）带走大量的热量。
参考答案：蒸发
— Do you know the Great Pyramid in Egypt?
— Of course. It is ______ building in the world. [ ]
A. the old and greatest
B. old and great
C. the oldest and greatest
制药工业的特殊性主要表现在哪几方面？
