单项选择题
Flame failure in an automatically fired auxiliary boiler can from a/an （）
A.incorrect electrode setting B.incorrect nozzle position C.clogged fuel nozzle D.broken high tension lead
单项选择题 Cold weather starting of a diesel engine may be made easier by（）
单项选择题 Diesel engine air start system check valves are opened by （）
单项选择题 The cetane rating of diesel fuel is an indication of the （）
