單項(xiàng)選擇題

公稱(chēng)直徑在65mm-200mm之間的金屬密封閥門(mén)嚴(yán)密性試驗(yàn)和強(qiáng)度試驗(yàn)的時(shí)間分別是()

A.20s,10s
B.30s,20s
C.30s,40s
D.30s,60s

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