可持续性不仅仅是一个流行词;它是对未来世代的承诺。
The act of writing is an act of optimism. You would not take the trouble to do it if you felt it didn't matter.
If one only wished to be happy, this could be easily accomplished; but we wish to be happier than other people, and this is always difficult, for we believe others to be happier than they are.