Program testing can be used to show the presence of bugs, but never to show their absence!

生活要么是一次大胆的冒险，要么什么都不是。

The reason that the invisible hand often seems invisible is that it is often not there.

孔子站在岸上指着河水说：“时光的流逝就像这河水一样！日夜不停地流去。”

学习是一生的旅程。