Hauj lwm lawm
Xa kev nug
manhole nrog union pom iav
Manhole nrog pom iav, qhov no yog qhov kev xaiv hloov tau, koj tuaj yeem xaiv txhua hom manhole los nruab nrog lub koom haum pom iav, kom yooj yim tshawb xyuas sab hauv lub tank.
