zoo koob tshuaj sib npaug
Qhov koob tshuaj zoo sib npaug sawv cev rau koob tshuaj tiv thaiv hluav taws xob ntawm tag nrho lub cev, uas yog siv los soj ntsuam qhov tshwm sim uas hluav taws xob yuav ua rau peb muaj kev noj qab haus huv, thiab suav cov xwm txheej tiv thaiv hluav taws xob. Nws yog txhais tias qhov tawm ntawm cov khoom lag luam ntawm qhov sib npaug koob tshuaj (HT) ntawm txhua cov ntaub so ntswg lossis hloov khoom nruab nrog thiab cov ntaub so ntswg sib npaug ntawm qhov hnyav (WT).