单项选择题
公称直径在65mm-200mm之间的金属密封阀门严密性试验和强度试验的时间分别是()
A.20s,10s
B.30s,20s
C.30s,40s
D.30s,60s
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单项选择题
A.20s,10s
B.30s,20s
C.30s,40s
D.30s,60s