Underdrainage
n. 暗渠排水, 地下排水
🗣️ 情景例句
Thank you for calling us.
谢谢你打电话给我们。
I hope you can pass the examinations.
我希望你的考试能通过。
Often the little words have meanings of their own.
这些小词常常都有自己本身的意思。