要理解递归，首先必须理解递归。
To understand recursion, one must first understand recursion.
Facts do not speak for themselves. They speak for or against competing theories. Facts divorced from theories or visions are mere isolated curiosities.
Every piece of plastic we produce should have a clear path to being reused or recycled.
The greatest disability is a bad attitude.
中庸：不走极端。对别人的伤害保持隐忍，将此视为应得之事。
The best leaders are those most interested in surrounding themselves with assistants and associates smarter than they are.
Sustainability isn't a choice—it's our responsibility to future generations.