精品无码久久久久久国产_成人午夜在线视频一区_亚洲最大的av网站_亚洲欧美综合区自拍另类_91精品国产一区_日韩精品中文在线观看_一道本无吗dⅴd在线播放一区_国产精品旅馆在线_欧美午夜久久久_亚洲自拍在线观看_黑人精品xxx一区一二区_亚洲精品日韩久久久_在线视频一区二区_国产欧美久久一区二区_中文字幕精品在线视频_成人欧美在线观看

Mathematics is not just about numbers, equations, computations, or algorithms: it is about understanding.

寫作是一種發(fā)現(xiàn)你未曾意識到自己已知之事的方式。

"The mind is not a structure but a process."

It's on the strength of observation and reflection that one finds a way. So we must dig and delve unceasingly.

圖書館里充滿了思想——也許是最危險和最強大的武器。