单项选择题
The ignition quality of a diesel fuel oil is indicated by the （）
A.specific gravity B.cetane number C.viscosity D.calorific valve
单项选择题 Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?（）
单项选择题 The cetane rating of diesel fuel is an indication of the（）
单项选择题 The cetane number of a diesel fuel oil indicates its（）
