我不是光明，我是黑暗。

逻辑学的研究是关于正确推理原则的研究。

Randomized evaluations can help us understand what works and what doesn't in development.

I believe in being strong when everything seems to be going wrong. I believe that happy girls are the prettiest girls. I believe that tomorrow is another day and I believe in miracles.

我们不是从经验中学习……我们是从对经验的反思中学习。