portal-in洞口: the mouth of a cave开挖: excavate; working洞口: entrance to a cave开挖: excavate; working◇开挖机 backactor; drag shovel; 开挖设备 excavation equipment; 开挖机械 excavation machinery导洞口: heading collar下载手机词典可随时随地查词查翻译关注微信公众号：chachacidian，回复:洞口开挖，即可在微信中查询翻译
