常見例句雙語例句Contractors are not allowed to use any kinds of installations as water , gas , valve , hydrant and electronic switches etc. without permission .搭建方不準(zhǔn)擅自動用展館的各種工程設(shè)施（指水、氣、閥門、消火栓、電器開關(guān)等） 。 返回 hydrant valve