一E801030室內輕鋼架工程業︵在客戶處作業︶.二E599010配管工程業︵在客戶處作業︶.三E604010機械安裝業︵在客戶處作業︶.四E603100電焊工程業︵在客戶處作業︶.五E603110冷作工程業︵在客戶處作業︶.