If I am counting upon a visit from a friend, who may be coming by train or by tram, I presuppose that the train will arrive at the appointed time, or that the tram will not be derailed.

• 如果我期望我的朋友前来看我，他可能坐火车或者电车前来，我预期火车将会在约定的时间到达，或者电车将不会出轨。