coal mine machinery

例句：

1. 1.The coal mine machinery is essential for the operation of the mine.
   煤矿机械对于矿井的运行至关重要。
2. 2. The new mining technology has greatly improved the efficiency of coal mine machinery.
   新的采矿技术大大提高了煤矿机械的效率。
3. 3.The coal mine machinery is a complex system that requires careful maintenance to ensure its safety and reliability.
   煤矿机械是一个复杂的系统，需要仔细维护以确保其安全和可靠性。