再过不到一年，人类将迈入新的世纪。我们在回顾20世纪的历程时，飞机的发明无疑是本世纪最伟大的事件之一，它改变了人类交往的时空观，使地球变得越来越小。现在的民航客机越造越大，一种可一次载运500～600乘客的超大型客机已在研制之中；速度也越来越快，超音速跨大气层飞 In less than a year, mankind will enter a new century. As we recall the course of the 20th century, the invention of the aircraft was undoubtedly one of the greatest events of this century. It changed the time-space concept of human interaction and made the Earth smaller and smaller. Now that the more civil aviation airliners are built, a very large passenger aircraft capable of carrying 500 to 600 passengers at a time has been developed; the speed is getting faster and faster, the supersonic cross-strait flight