A smoking exhaust from an operating diesel engine could be caused by( ).
A.low sulfur content in the fuel
B.a loose injector inlet connection
C.late fuel injection
D.high injection pressure
正确答案：C解析：sulfur/sulphur：硫;content：内容，含量译文：运行中的柴油机冒黑烟，可能的原因是燃油喷射滞后。
