A.500mm B.630mm C.800mm D.1000mm
A.3m B.3.5m C.4m D.4.5m
金屬矩形風(fēng)管長(zhǎng)邊b=1600mm,當(dāng)風(fēng)管進(jìn)行連接時(shí),法蘭和螺栓規(guī)格分別是()
A.A B.B C.C D.D