水汽达到过饱和状态的途径：一是增加大气中的（）含量，二是使含有一定量水汽的空气（）。
参考答案：水汽；降低温度
经营思想
─ There is some soup on the table, isn't ____?
─ No, I think that's water. [ ]
A. there
B. it
C. that
D. one
