N-COUNT (位于街面，盖有金属盖，供工人检修、疏浚下水道时出入的)出入孔，检修孔，人孔 A manhole is a large hole in a road or path, covered by a metal plate that can be removed. Workers climb down through manholes when they want to examine or clean the drains. (位于街面，盖有金属盖，供工人检修、疏浚下水道时出入的)出入孔，检修孔，人孔