qhov rooj rooj yog dab tsi?

Cov kab hlau uas nyob ib puag ncig lub qhov rooj hu ua casing, thiab nws ib txwm ntsia ua ntej lub hauv paus thiab lub rooj zaum kev tsheb nqaj hlau vim tias lawv yuav tsum sib tw nrog nws. Casing tseem yog hom yooj yim moulding rau nruab vim tias joinery yog yooj yim, ua rau nws ua qhov project zoo meej.