bị ô nhiêm nặng 
to be heavily polluted [ bị ] : (1) bag, (knap)sack; (2) to suffer, undergo, experience, (suffering passive marker); (3) to prepare for in advance
[ ô ] : (1) suburb, (2) umbrella
[ nặng ] : (1) heavy, weighty, serious, ponderous; (2) low-constricted tone
Most Common Compounds Set 1:
Most Common Compounds Set 2 :