large ballast undercutting cleaners

例句：

1. 1.The engineers were responsible for the entire undertaking.
   工程师们负责整个工程。
2. 2.The undertaking was completed within the agreed time frame.
   工程在约定的时间内完成了。
3. 3. The undertaking involved a significant amount of research and development.
   这个工程涉及大量的研究和开发。
4. 1. The cleaners are responsible for maintaining the cleanliness of the workplace.
   清洁工负责保持工作场所的清洁。
5. 2. The cleaners are expected to follow strict hygiene standards.
   清洁工应遵循严格的卫生标准。
6. 3. The cleaners were hired to ensure the proper sanitation of the building.
   清洁工被雇佣以确保建筑物的适当卫生。