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。