短语词组短語gas extraction hole 瓦斯抽放孔gas drilled hole 天然氣鑽井gas valve hole 氣閥孔gas sampling hole 氣躰採樣口;氣躰取樣孔gas expansion hole 氣脹孔gas firing hole 氣眼gas escape hole 排氣孔gas drainage hole 瓦斯抽放孔gas outlet hole 氣躰出口孔 返回 gas hole