boiler improvement

例句：

1. 1. The company isinvesting heavily in improving the efficiency of itsboilers.
   该公司正在大力投资于提高其锅炉的效率。
2. 2. The engineer made a significant improvementto the design of the boiler.
   工程师对锅炉的设计做出了重大改进。
3. 3. The newmodel boiler has been designedwith improved safety features.
   新型锅炉设计了改进的安全特性。