Britain's Royal Society has released a report looking at how science and technology can be used to fight a food shortage it says is expected to hit the globe by 2050.

VOA: standard.2009.10.21

so we know how to do this, and we know this thing when it hit these stops, v2 the pressure with p2, and the volume was V2.

所以我们知道怎么计算，当活塞到达这两个挡板时，压强是p2，体积是。

麻省理工公开课 - 热力学与动力学课程节选