diesel-mechanical locomotive

例句：

1. 1.The diesel-mechanical locomotive is the backbone of our transportation system.
   柴油机械机车是我们交通系统的核心。
2. 2.The diesel-mechanical locomotive has been upgraded to improve efficiency and reduce emissions.
   柴油机械机车经过升级，以提高效率并减少排放。
3. 3.The diesel-mechanical locomotive is a reliable and efficient mode of transportation.
   柴油机械机车是一种可靠且高效的运输方式。