Each gas diffuses down its own partial pressure gradient - that is, from a high to low partial pressure.

每种气体都会沿着它自己的分压梯度扩散——也就是说，从高分压扩散到低分压。

The lung pressure (or more specifically, intrapulmonary pressure), becomes less than atmospheric pressure, and that creates a pressure gradient, or a difference between the two pressures.

肺压力（或者更具体地说，肺内压力）变得比大气压力小，这就产生了压力梯度，或者两种压力之间的差异。