单项选择题
A.阀杆B.阀芯C.阀位D.阀门
A.0.1~10B.0.2~5C.0.5~2D.0.1~2
A.0.5~0.55MPaB.0.57~0.62MPaC.0.62~0.65MPaD.0.65~0.68MPa