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A man is rich in proportion to the number of things which he can afford to let alone. That man is the richest whose pleasures are the cheapest.

一本好書是一位偉大的老師。

數(shù)學(xué)的目標(biāo)是理解我們觀察到的現(xiàn)象背后的結(jié)構(gòu)。

For all that has been, thank you. For all that is to come, yes!