善行本身就是一种幸福的行为。
An act of goodness is of itself an act of happiness.
农业效率必须与生态限制相协调——我们无法超越自然。
在学习结束时,我们知道物理学的所有过去,但对现在和未来一无所知。
The greatest gift you can give someone is your time.
The history of the world is the history of the few.