Happiness is a state of mind, not a set of circumstances.

I don't think limits.

I am made and remade continually. Different people draw different words from me.

Free education is abundant, all over the Internet. It's the desire to learn that's scarce.

如果你懂得倾听，死者也会开口。

地质学是研究自然界有机和无机领域连续变化的科学。