motor-generator locomotive

例句：

1. 1. The engineers designed the new motor-generator locomotive to improve efficiency.
   工程师们设计了新型的机车来提高效率。
2. 2. The old steam locomotive was retired after many years of service.
   这台老式蒸汽机车在服役多年后被退役。
3. 3. The locomotive was used to transport coal from the mine to the factory.
   这台机车用于将煤炭从矿井运送到工厂。