underground ice地下冰undergroundadj.地下的；秘密的adv.在地下；秘密地n.地下；地铁；地道；秘密活动underground catalytic gasification地下催化气化underground diagenetic environment地下成岩环境underground wireless communication井下无线通信underground criminal investigation卧底侦查underground air defense facilities地下人防underground coal banker engineering井下煤仓工程underground drinking water resource地下水资源underground water level observation地下水位观测Underground industrial architecture地下工业建筑underground culvert of Yantun river杨屯河地下涵洞