qua nhiều thế hệ 
over, through many generations [ qua ] : after, by, through, over; last (week, day, etc.); to pass by, go across, cross over
[ nhiều ] : much, many, a great deal, plentiful, often, numerous, abundant, a great deal
[ thế ] : (1) manner, way, fashion, position, situation, posture; (2) so, thus, like that, such
[ hệ ] : branch, system; generation
Most Common Compounds Set 1:
Most Common Compounds Set 2 :