【答案解析】It is universally (generally) believed that the plane (air travel / traveling by air) is the quickest way (form) of transportation. There is, however, the concern (fear) about its safety. In fact, far more people die from traffic accidents than from air crashes (traffic accidents kill many more people / claim (take) far more lives than) annually. The reason why most people choose the train is to save money (that they can save money), at about a quarter of the cost (expense) of the plane. With the continuous improvement of the living standard (as... keeps improving) in China, more and more (an increasing / growing number of) people prefer / opt for air travel (to take a plane) to save time. Railway authorities have been working hard (made constant effort) to accelerate / speed up the passenger train to enhance (improve) their competitiveness (competitive edge).