I'd chosen to travel by rail not for any anoraky reasons, but because I have always found a train, particularly a slow train, a good way of taking the pulse of a place.
我选择坐火车旅行因为我发现坐火车，尤其是慢车是观察一个地方很好的方式。
2
If the modulation rate is high, it is possible to smooth out the pulsetrain using passive electronic filters and recover an average analog wave form.
如果调制率高，是有可能顺利进行，脉冲列车使用被动电子过滤器和收回平均模拟波形。
3
Level dropout: This detects an edge followed by a specified time with no edges. It is useful for triggering on the end of a pulsetrain.