设计背景有一次星期天上午,我随爸爸到奶奶家去玩,途中我们看到一起发生在十字路口的交通事故。询问现场目击者后,我了解到事故的起因是因为路边有树木挡住视线,不知横向路道有车辆在行驶,避让不及导致相撞事故发生。一路上我就在想,如果路边没有树木挡住视线,也许就不会发生这样的悲 Design Background There was a Sunday morning, I went to my grandmother with my father to play, on the way we saw the accident occurred at a crossroads. After I asked the scene witnesses, I learned that the cause of the accident was because trees were blocking the line of sight on the curbside. I do not know if there was a vehicle moving in the horizontal road and could not avoid the accidental collision. I was thinking all the way, if the roadside trees do not block the line of sight, may not happen so sad