coal hole cover

例句：

1. 1.The miners had to cover the coalhole with a large sheet of metal.
   矿工们不得不用一块大金属板覆盖煤洞。
2. 2. The engineers carefully placed thecoal hole cover before starting the drillingoperation.
   工程师们在开始钻探作业之前仔细地放置了煤洞盖。
3. 3. Thecoal hole cover was designed to protect theworkers from falling debris.
   煤洞盖的设计是为了保护工人免受坠落物的伤害。