单选题
1分
Fuel of different qualities may require advancing or retarding the injection timing, in addition to ...
Fuel of different qualities may require advancing or retarding the injection timing, in addition to which if the injection timing is advanced when the engine is running at loads below the ____.
参考答案: B
参考解析: 注:除了柴油机在低于最大持续功率下运行时喷油定时要提前外,不同质量的燃油需要喷油定时提前或延迟。