A problem of mechanics is not solved until it has been reduced to a problem of algebra.
一个力学问题只有被简化为代数问题时才算解决。
Your voice can change the world.
The foundation of morality is sympathy for others.
让我们清楚一点:只是限制广告不健康的食物是不够的。增加对健康食品的'营销也很关键。