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。
At the close of our studies， we knew all the past of physics， but nothing of the present and the future.
The desire for recognition, the thymotic part of the soul, is the most political part of man.
可持续性不是一种选择，而是我们共同的责任。
You cannot step into the same river twice.
今天放归大海的每一条鱼都是对未来渔获的投资。