The greatest threat to our forests isn’t logging—it’s indifference.

自由在于勇敢。

兴趣越浓厚，记忆越生动。

这就是学习。你突然以一种新的方式理解了你一生都在理解的东西。

He allowed himself to be swayed by his conviction that human beings are not born once and for all on the day their mothers give birth to them, but that life obliges them over and over again to give birth to themselves.

The internet is a tool that can be used for good or bad, and it's up to us to decide how we use it.

在数学中，提出问题的艺术必须比解决问题更有价值。