你唯一必须知道的就是图书馆的位置。
The only thing you absolutely have to know is the location of the library.
你知道 72 法则,将数字除以 72,你想要的任何数字,这就是你的钱翻倍需要多长时间。
The true cost of oil isn't just the price per barrel—it's the environmental and social impact.