An instructor in chemical warfare asked soldiers in his class: Anyone knows the formula for water?

　　Sure. That's easy, said one man.

　　What is it?

　　H, I, J, K, L, M, N, O.

　　What, what? reasked the instructor.

　　H to O, explained the chemistry expert.

　　生化战争课的老师在课堂上问士兵们：谁知道水的分子式？

　　当然，太简单了。一个士兵回答道。

　　是什么？

　　H, I, J, K, L, M, N, O.

　　什么，什么？老师又问道。

　　H to O，化学专家解释道。