At points where vehicles may approach the excavation, stop logs must be placed at a safe distance. 在车辆可能靠近挖掘作业区的地点，必须在安全距离处设置停止标志。
This kind of thinking does not consider the fact that oil distance and where the ball leaves the oil pattern and enters the dry backend. 这种逻辑并没有将油的长度及球出油区进入干燥区的距离考虑进去。
