They just keep trotting back and forth across the bridge thinking there is something better on the other side. If they'd hang head down at the top of the thing and wait quietly, maybe something good would come along. But no—with men it's rush, rush, rush, every minute. I'm glad I'm a sedentary spider.

The improvement of understanding is for two ends: first, our own increase of knowledge; secondly, to enable us to deliver that knowledge to others.

The dead are invisible, but they are not absent.

每回收一吨纸就能拯救17棵树，这不仅是生意，更是留给后代的遗产。