Thawj chav yog tib yam li qhov thib ob. Yog tias ntxiv dej ces chav tsev tuaj yeem siv los tshem tawm cov hmoov luam ntawv. Chav tsev thib ob yog tus tsim peb-cov menyuam, uas nws cov menyuam roj hmab siv cov khoom siv tshwj xeeb kom nws tuaj yeem sib npaug ntawm cov khoom siv nrog cov txiaj ntsig zoo. Thiab nws haum rau dej-raws li / roj-raws li roj thiab cov kua roj vanish, thiab lwm yam. Lub tsev tuaj yeem hloov kho tau yooj yim ntawm ib sab.