解释：不可以不知道活着的乐趣，也不可以不知道虚度光阴的担忧。

每一个超限的一致多重性，即每一个超限集合，必须有一个确定的阿列夫作为其基数。

The biggest risk is not taking any risk. In a world that’s changing quickly, the only strategy that is guaranteed to fail is not taking risks.

过度捕捞是短视行为，我们必须为子孙后代留下丰饶的海洋。

我们要以开放合作的态度，加强国际能源合作，实现互利共赢。

如果我们明智地使用技术，它可以成为林业最伟大的盟友。

I constantly see people rise in life who are not the smartest, sometimes not even the most diligent, but they are learning machines. They go to bed every night a little wiser than they were when they got up.