Life is like a piano. The white keys represent happiness and the black keys show sadness. But as you go through life's journey, remember that the black keys also create music.

释义：世上的许多人为了利益，不惜冒生命危险，甚至到了无路可退的地步也不愿放弃。

最好的科学往往来自于提出最简单的问题。