Lub freshness ntawm cov ntses qhuav yog qhov nyuaj rau qhia los ntawm cov tsos, tab sis nws tsis' t txhais tau tias tsis muaj txoj hauv kev. Ua ntej peb tau hnov tus ntxhiab tsw: muab cov ntses ziab hauv qab qhov ntswg, ua pa, thiab tsw yog tias muaj tus ntxhiab tsw txawv, hluav taws-tsw thiab pa tsw qab yog pom tseeb; qhov thib ob, endoscope: rhuav cov ntses qhuav ib qho me me, saib Seb puas yog cov nqaij zoo thiab kaw ntom nti, yog tias nws yog xov, nws zoo zoo, yog tias nws tsis yooj yim, nws yog qhov tsis zoo. Fenfan feem ntau tsis tiav los ntawm ntses tshiab. Feem ntau ntawm cov hau kev siv tau saj cov zaub mov siav, yog li nws pom zoo kom yuav tsawg dua ib zaug, thiab tom qab ntawd rov qab los tom qab saj.
Ntxiv rau, qhov zoo ntawm cov pob dawb - dawb tsis yog dawb li qhov ua tau, thiab qee cov ntsej muag yog kho nrog alum. Cov tawv dawb pob yog ci thiab ntuj dawb thiab pob tshab.