同流合污: associate oneself with undesirable elements [trends]; associate with evil elements; birds of a feather flock together.; evil companions associate in evil.; foul one's hands with sb.; go al
跟上: keep pace with; catch [keep] up with; keep [be] abreast of [with]: 跟上时代的步伐 keep pace with the times; 跟上科学上的最新发展 keep up with the latest development in science; 跟上形势 keep abreast of the cur