释义：知足常乐的人会感到快乐，没有欲望没有追求的人会感到轻松。

"The challenge is to make the invisible visible."

我喜欢那种比以往任何时候都更用力击球的感觉。

The power of a computational model is not just in its ability to compute, but in its ability to generalize from specific instances.