当你最不抱期望时，研究的坚持往往会带来回报。
Persistence in research often pays off when you least expect it.
"A literatura não tem fronteiras, ela transcende culturas e línguas."
Natural experiments are a powerful tool for understanding causal relationships in the real world.
The best way to get something done is to begin.
写作是理解我们在历史中位置的一种方式。