Underdrain
n. 阴沟, 地下沟道, 盲沟, 暗渠
🗣️ 情景例句
Have you ever been to Niagra Falls?
你去过尼亚拉加瀑布吗？
If he doesn't play, who will?
如果他不，谁要去玩？
There are a lot of people in the swimming pool.
游泳池里挤满了人。