air-fuel ratio

例句：

1. 1.The engine's efficiency is directly related to the air-fuel ratio.
   发动机的效率与空气燃料比直接相关。
2. 2. In order to improve fuel efficiency, the manufacturer adjusted the air-fuel ratio.
   为了提高燃油效率，制造商调整了空气燃料比。
3. 3.The pilot carefully monitored the air-fuel ratio to ensure safe operation of the aircraft.
   飞行员仔细监控空气燃料比，以确保飞机的安全运行。