天有不测风云yīngwénjièshì:
  • n.  Anything unexpected may happen. a bolt from the blue;out of the blue
  • n.  sth. may happen any time,as a storm may arise from a clear sky
  • n.  Human fortunes are
  • n.  as unpredictable as the weather

(fēizhùcèchéngyuánměiyèzànxiàn 4 lì)