色多多在线观看播放-色多多在线观看高清免费-色多多在线观看视频-色多多在线看-欧美aaaaa性bbbbb小妇-欧美aaaav免费大片

The revolution is not an apple that falls when it is ripe. You have to make it fall.

The best scientists are those who remain humble in the face of nature’s complexity.

I'm not afraid of the dark; I'm afraid of what's in it.

最好的領導者是那些傾聽多于發言并以誠信行事的人。

Literature is a way to keep the fire of humanity alive.

定理是數學的里程碑。