manhole with horizonal hanging cover

例句：

1. 1. The manhole was covered with alayer of dirt.
   这个地洞被一层土覆盖着。
2. 2. The manhole led toa small tunnel.
   这个地洞通向一个小隧道。
3. 3. The manhole was used to ventthe exhaust gases from the engine.
   这个地洞用来排放发动机的废气。