I don't have any particular recipe [for developing new proofs] ... It is the reason why doing research is challenging as well as attractive. It's like being lost in a jungle and trying to use all the knowledge that you can gather to come up with some new tricks, and with some luck you might find a way out.
你最不满意的顾客是你最大的学习来源。
地理学是研究地方的科学。它的视野宏大,视角全景。