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

音乐无处不在，世界唱出赞歌。

没有比一个除了优柔寡断之外没有任何习惯的人更悲惨的了。

If you're not stubborn, you'll give up on experiments too soon. And if you're not flexible, you'll pound your head against the wall and you won't see a different solution to a problem you're trying to solve.

可持续发展不仅对地球有益；它对商业有益，对长期成功至关重要。