I have lived with the prospect of an early death for the last 49 years. I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first.
在我过去49年的生命中，早逝的可能性一直存在。我不畏惧死亡，但我不想早早离去。我还有很多未竟之事。
Natural experiments are a powerful tool for understanding causal relationships in the real world.
Enduring peace cannot be bought at the cost of other people's freedom.
可能的原因，我不知道为什么，但我观察到了它。