việc phải làm 
necessity, something that has to be done [ việc ] : affair, thing, work, job, matter, business, idea
[ phải ] : (1) correct, right (opposite of left), right (opposite of wrong); (2) must, have to
[ làm ] : to do, work, make, function as, serve; to cause something to happen
Most Common Compounds Set 1:
Most Common Compounds Set 2 :