点解下水道的盖是圆形的？
下水道出入孔：一种常带有盖的孔道，人可以由此孔进出排道、锅炉、下水管或类似设施。
A hole, usually with a cover, through which a person may enter a sewer, boiler, drain, or similar structure.
今天我坐摩的的时候翻车了，后背摔在一个没盖盖子的下水道上。
Today, I was taking a motorcycle taxi, when we lost balance and toppled over. I fell on my back on an open sewer.
为什么下水道癿亐盖是囿癿？
下水道防污盖，由孔板折边制成托盘形盖。
The utility model relates to an antifouling cover of a sewer.
下水道防污盖，由孔板折边制成托盘形盖。
The utility model relates to an antifouling cover of a sewer.
应用推荐