在一定的温度条件下，空气中的实际水汽含量与其能容纳的最大水汽含量的比率叫做（）.
A.露点
B.饱和点
C.相对湿度
参考答案：C
There aren’t any___ between them.
A．different
B．difference
C．more different
D．differences
The poor lady had to go out for food a cold morning.[ ]
A.in
B.at
C.on
D.during
