So many years. I always confused in some principle(i mean sharp pointed)questiones. first one is the biggest one. How to explain the Poluly equation(i mean the relationship between the speed and pressure) in the level of microcosmical. (spoted! i mean the level of microcosmical but not consider the atomic reactions,we just consider it's a lot of small ball,as small as possball) I think this equation is a very simple very beautiful equation.So there must be a very beautiful and very wonderful and very depth and very interesting reasones.