chinh chuyQundn nQundng hiQundn gian trong cQundng nhiQundm tinh cQfng trQundng giup phQundm viQundc mQundt khi quyQundn tQfm hQundng cQfn lQundy lQundch vQundt khac thQundy giQundi xay khong kQundt mQundc nhien iQundm chiQundn mQundng thQundng mQfnh