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

真相并不總是美麗的，美麗的話語也不總是真相。

Fear not for the future, weep not for the past.

"Education is the most powerful weapon which you can use to change the world."

人心如海：有風(fēng)暴，有潮汐，有深淵；其中也有珍珠。

A mathematician is a person who can find analogies between theorems; a better mathematician is one who can see analogies between theories and the best mathematician can notice analogies between analogies.