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 best way to predict the future is to create it.
你把桃子投于我,我把李子回赠与你。桃子和李子价值相当,表明我本人是知恩图报的,也有互相赠送,礼尚往来的意思。