单选题
1分
Black smoke exhausting from an operating diesel engine is an indication of poor combustion which may...
Black smoke exhausting from an operating diesel engine is an indication of poor combustion which may be caused by ________.
参考答案: C
参考解析: 注:运行的柴油机冒黑烟表明燃烧不良,这可能是由于进气管路堵塞引起的。