steel-smelting furnace

例句：

1. 1.The steel-smelting furnace is the heart of the steel plant.
   炼钢炉是钢厂的核心。
2. 2. The steel-smelting furnace is essential for producing high-quality steel.
   炼钢炉对于生产高质量钢材至关重要。
3. 3. The steel-smelting furnace is a complex machine that requires skilled operators.
   炼钢炉是一个复杂的机器，需要熟练的操作员。