The secret of change is to focus all your energy not on fighting the old, but on building the new.

The essence of mathematics is not to make simple things complicated, but to make complicated things simple.

从长远来看，经济前景是乐观的，但从长远来看，我们都死了。

The city is a book written by its inhabitants.

可持续发展不仅是一种趋势，更是一种责任。