"To train a hawk you must watch it like a hawk."
The problem is not that we laugh too much， but that we laugh about everything.
What I want to talk to you about today is the difference between gifts and choices. Cleverness is a gift， kindness is a choice. Gifts are easy -- they're given after all. Choices can be hard. You can seduce yourself with your gifts if you're not careful， and if you do， it'll probably be to the detriment of your choices.
大国总是在寻找机会以牺牲对手为代价来获取权力，如果他们认为使用武力会带来利益，他们就会使用武力。
膨胀的概念表明，宇宙在大爆炸后不久经历了一段极其快速的扩张期。
