Feem ntau, cov qhov rooj hluav taws uas tau teeb tsa rau hauv cov tsev tsis muaj cov kev cai tshwj xeeb ntawm cov khoom siv dab tsi, tab sis qhov kev coj ua peb siv tiag tiag yog cov qhov rooj hluav taws hauv tsev feem ntau yog ua los ntawm cov ntoo, thiab cov qhov rooj hlau sab nraum zoov siv. Lub sijhawm tiv thaiv hluav taws ntawm lub qhov rooj hluav taws yog ntev lossis luv, txais tos nrog peb tham.