有一个问题曾经百思不得其解:早先的汽车上,是没有转向灯的,那么,如何告诉别人我要转弯呢?后来在一部黑白谍战片里找到了答案:我公安干警开的吉普车风挡玻璃后面,有一个可以转动的箭头。要向哪里转弯,就手动把箭头朝那个方向转去,交通警察或者迎面来车来人,就知道你要朝哪里转向了。这种原始的转向示意方式,存在了几十年,似乎也没有出过什么大的问题。幸亏那个时候车少,要是放在 There was a problem once baffled: the previous car, there is no turn lights, then, how to tell others I want to turn it? Later in a black and white spy war movie found the answer: I police opened a jeep Behind the windshield, there is a rotating arrow. Where to turn to manually turn the arrow in that direction, the traffic police or oncoming traffic came to know where you turn toward. This primitive way of steering has existed for decades and seems to have not caused any major problems. Fortunately, when the car less, if placed