So I'm ready to go." In other highlights Thursday, medals will be up for grabs in the men's 200 meters, Qualifying heats also begin in the men's 800 and 5,000 meters, and women's hammer throw, The women will also try to advance to Friday's 200-meters final.

VOA: standard.2009.08.19

You know, you mix acid and base together and the thing heats up like crazy, right.

你知道，当你把酸和碱混合起来时,这东西会像疯了一样地变热。

麻省理工公开课 - 热力学与动力学课程节选