好景不常
the morning sun never lasts a day.
the longest day must have an end.
every day is not sunday.
a wonder lasts but nine days.
eg：the social disorder destroyed the once prosperous town, the morning sun never lasts a day.
中英俚语俗语来源：王勃·滕王阁序：“好景不常，盛延难再。”
反义词：天下无不散之延席 merry meet， merry part.
