因为温暖的空气比冷空气能容纳更多的湿气，所以只有当大气中的水蒸气量随着温度的升高而增加时，相对湿度才会保持不变。

Because warm air can hold more moisture than cool air, the relative humidity will be constant only if the amount of water vapor in the atmosphere increases as the temperature rises.

youdao

利用能源回收技术，水蒸气的经济效益达到25％到30％（产生气体量占使用蒸气量的百分比）。

Using energy recovery technologies, steam economies of up 25% to 30% (mass of vapor produced per mass of steam used) can be attained.

youdao

利用能源回收技术，水蒸气的经济效益达到25％到30％（产生气体量占使用蒸气量的百分比）。

Using energy recovery technologies, steam economies of up 25% to 30% (mass of vapor produced per mass of steam used) can be attained.

youdao