At that age， I'd take any excuse to make estimates and do minor arithmetic. I'd calculate our gas mileage -- figure out useless statistics on things like grocery spending. I'd been hearing an ad campaign about smoking. I can't remember the details， but basically the ad said， every puff of a cigarette takes some number of minutes off of your life: I think it might have been two minutes per puff. At any rate， I decided to do the math for my grandmother. I estimated the number of cigarettes per days， estimated the number of puffs per cigarette and so on. When I was satisfied that I'd come up with a reasonable number， I poked my head into the front of the car， tapped my grandmother on the shoulder， and proudly proclaimed， "At two minutes per puff， you've taken nine years off your life！"

可持续性不是一种选择，而是我们对下一代的责任。

"A story is not like a road to follow... it's more like a house. You go inside and stay there for a while."

勇气并不意味着你不害怕，而是你不让恐惧阻止你。

每首歌都有自己的生命。

模型检查的挑战不仅在于发现错误，还在于理解它们为何发生。

Science is not just about accumulating facts; it's about understanding the mechanisms behind them.