40 years long, with an overlap. You can put that statement on all kinds of different technologies. The interesting thing -- by the way, the speed here, excuse me, higher-speed travel is the title of these innovation cycles. There is none here.
持续40年的时间，有些周期相互交叠。你可以将此观点 放至不同的科技。这有趣的事情-- 顺便一提，这里的速度，不好意思，高速旅行 是这些发明创造周期的标题。这里没有一个。