单项选择题
A smoking burner with a pulsating flame in auxiliary boiler, is an indication that the（）
A.fuel oil supply temperature is normal B.burner electrode is incorrectly positioned C.fuel／air ratio is incorrect D.ignition current is too low
单项选择题 The correct procedure for giving an auxiliary boiler a bottom blow, is to begin（）
单项选择题 Bottom blow valves are installed on auxiliary water-tube boilers to （）
单项选择题 A burner responsible for producing black smoke in an automatic auxiliary boiler, would be caused by a （）
