BARACK OBAMA: "That is why, even as it cuts back on programs we don't need, the budget I submit will invest in the three areas that are absolutely critical to our economic future: energy,health care,and education."

VOA: special.2009.02.27

And, when zinc sulfide is hit by particles or by anything, by radiation or by particles of greater than a certain critical energy, there is a glow.

当粒子或其他东西,通过辐射或粒子的方式，并且能量高于临界值,撞击到硫化锌的表面上的时候，就会发光。

麻省理工公开课 - 固态化学导论课程节选

Russia then, Russia's energy sources are critical.

俄罗斯能源资源至关重要。

普林斯顿公开课 - 国际座谈会课程节选