One should expect that the expected can be prevented, but the unexpected should have been expected.

One should expect that the expected can be prevented, but the unexpected should have been expected.

人们应该预料到意料之中的事情是可以预防的，但是意料之外的事情是应该预料到的。

-- Norman Ralph Augustine 诺曼·拉尔夫·奥古斯丁