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

數學中真正的挑戰不是解決問題，而是提出正確的問題。

I never buy anything unless I can give a good reason why I think it will go up.

"The past is always present in our lives, whether we acknowledge it or not."

最偉大的發現往往來自于冒險和跳出框框思考。

The most important political challenge of our time is to create strong, effective, and accountable states.

科學不僅僅是發現新事物，還包括提高世界各地人們的生活質量。

The industry must collaborate to reduce its environmental footprint.

我不會因為累而停止，我會因為完成而停止。