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

最深刻的理論往往源于最簡單的觀察。

Curiosity is the engine of intellectual achievement, and humility is its compass.

The way in which men produce their means of subsistence depends first of all on the nature of the actual means they find in existence and have to reproduce.

我們必須立即行動，因為海洋的衰退是我們不能忽視的危機。

科學中的每一個發現都是建立在我們之前無數人工作的基礎上。

Trust is the foundation of every successful business relationship.