underdrain distributor排水配水器
circular underdrain环向盲沟
Underdrain system配水系统
underdrain equality布水均匀
longitudinal underdrain纵向盲沟
underdrain equipment底座排水装置;切割不足
brick underdrain砖砌阴沟
underdrain pipe暗管排水
Underdrain of filter滤池集水沟;[建] 过滤池暗沟
N（名词） a drain buried below agricultural land (农田的)暗渠
V（动词） to bury such drains below (agricultural land) (在农田下)埋暗渠