I'm a strong person, but I also have a lot of emotions.

The poor are not irrational; they are just as rational as anyone else, but they operate under very different constraints.

When we talk about food security, we're really talking about national security.

时间不是一条线，而是一个维度，就像空间的维度一样。

A proof of a proposition is a process the nature of which is such as to produce in us a belief in that proposition.

危机感要时刻保持。