The sun is our most powerful tool in Africa. We must learn to work with it, not against it.

You think when you wake up in the mornin yesterday don't count. But yesterday is all that does count.

建筑不在于形式，而在于许多其他事物。

一本好书是最好的朋友，今天如此，永远如此。

数学不是一项观赏性运动。