Trains travel regularly along the railway. 火車(chē)沿鐵路有規則地行駛。
One could station observers along the track and find the locations of the front and rear of the train at a particular instant of time. 可以沿鐵路沿線(xiàn)安排一系列觀(guān)察者,找出某一特定時(shí)刻火車(chē)頭尾的位置。