trong một thời gian lâu 
for a long time [ trong ] : during; in(side), among
[ một ] : one; a, an
[ thời ] : time(s), era
[ gian ] : (1) dishonest, underhanded, tricky; (2) apartment, room; (3) difficult, hard; (4) danger, peril
[ lâu ] : long (of time); to take a long time
Most Common Compounds Set 1:
Most Common Compounds Set 2 :