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The desires， and other passions of man， in themselves， are in his own power； his real difficulties are， to know when they are to be controlled， and when not.

數(shù)學(xué)之美在于它能夠以精確而優(yōu)雅的方式描述世界。

數(shù)學(xué)不是一項(xiàng)觀賞性運(yùn)動(dòng)。