烟雾曾经是A市的大景观,如今,从B国的C省至D城,全国各地,随处可见。人们对污染了的空气越来越习以为常了,以至于要让他们呼吸别的空气反倒十分困难了。最近,成功的商人张玄正在做巡回演讲,其中的一站是X州的Y地,这个地方的海拔在4000米以上。刚一下飞机,张玄就闻到了一种奇怪的 Smoke was once a big sight of City A. Today, it can be seen everywhere from the province of B to the city of D, and across the country. People are becoming more and more accustomed to polluted air, so that it is very difficult for them to breathe other air. Recently, Zhang Xuan, a successful businessman, is making a speech tour. One of the stops is the Y-land of X. The altitude of this place is above 4000 meters. Just after the plane, Zhang Xuan heard a strange