efficiency of heat engine

例句：

1. 1. The new machine has a much higher efficiency than the old one.
   这台新机器的效率比旧的要高得多。
2. 2.The teacher's teaching methods are very efficient in improving students' learning outcomes.
   老师的教学方法非常有效，能够提高学生的学习成果。
3. 3.The company's new policy is designed to improve its overall efficiency.
   公司的新政策旨在提高其整体效率。