The temperature remained constant while pressure was a variable in the experiment.
做这实验时温度保持不变，但压力可变。
《牛津词典》
2
I thought for a long time, a final decision, since to learn not to learn, to find their own some of the pressure and variablepressure as the power, the beginning of all from the heart.
我想了很久，最后决定，既然要学不如好好学，给自己找一些压力，变压力为动力，一切从心开始。
3
Presents an idea of variablepressure difference control, and analyses the electric saving effect of this control mode.