短语词组短語balanced -draft control 負壓調節;引風調節balanced healthy draft 均衡通風balanced draft boiler 平衡通風鍋爐balanced draft furnace 具有引風及鼓風的平衡通風爐膛balanced draft sampling 平衡吸氣取樣balanced draft system 平衡通風系統draft balanced 均衡通氣 返回 balanced draft