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Mathematics is not a careful march down a well-cleared highway, but a journey into a strange wilderness, where the explorers often get lost.

A good film is one that leaves you thinking long after it's over.

釋義：過于強硬的弓弦容易斷裂，過于鋒利的刀口容易受損。惹禍往往是因為多嘴多舌，招致災禍多是因為心腸狠毒。