炉口

例句：

1. 1. The fireman was trying to get the fire undercontrol by closing the furnace door.
   消防员试图通过关闭炉门来控制火势。
2. 2. The old stove had a small openingat the top that could be used asa furnace.
   旧式火炉顶部有一个小开口，可以用作炉子。
3. 3. Theengineer carefully inspected the furnace before startingthe engine.
   工程师在启动引擎前仔细检查了炉子。