show up简单

First two hours, now three hours — this is how far in advance authorities are recommending people show up to catch a domestic flight, at least at some major U.S. airports with increasingly massive security lines.

先是两小时，现在是三小时——这是当局建议人们为赶国内航班提前到达机场的时间，至少在一些安检队伍越来越长的美国大型机场是这样。