Underground car井下汽车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 parking system地下停车场系统underground electric borer潜水电钻Underground Water Pipeline地埋输水管线underground space resource地下空间资源underground water resource地下水资源underground cultural relic地下文物underground railway ticket地铁票underground diaphragm wall地下连续墙underground diversion wall地下导流墙underground packing garage地下存车库