单项选择题
A.打开火嘴、停止进油 B.熄灭火嘴、持续进油 C.熄灭火嘴、停止进油 D.打开火嘴、持续进油
A.30%~95% B.25%~90% C.20%~80% D.25%~80%
A.30%~95% B.20%~95% C.30%~100% D.40%~100%