A friend once told me of driving along a one-lane, unpaved mountain road.Ahead was another car that produced clouds of choking dust, and it was a long way to the nearest paved highway.

• 一位朋友曾经告诉我他开车行驶在狭窄的山间土路上，在他的前面有一辆车掀起呛人的尘土，他们离最近的柏油路也还有不短的距离。