A.20~60 B.20~50 C.0~20 D.10~50
A.打開火嘴、停止進油 B.熄滅火嘴、持續(xù)進油 C.熄滅火嘴、停止進油 D.打開火嘴、持續(xù)進油
A.30%~95% B.25%~90% C.20%~80% D.25%~80%