translation.en: So we, by making a whole bunch of attempts, thousands of attempts, in that four-year time period, we invented the concepts of the airplanes that we fly today. And that's why they're so safe, as we gave it a lot of chance to find what's good.
translation.zh: 所以我们，通过做一大堆尝试，几千次的尝试， 在那四年里，我们发明了 我们今天飞行所用的飞机。这就是为什么我们这么安全， 因为我们给了自己很多机会去发现什么是好的。