A.20db B.18db C.22db
A.基數(shù)波長(zhǎng),偶數(shù)波長(zhǎng) B.偶數(shù)波長(zhǎng),基數(shù)波長(zhǎng) C.后16波,前16波 D.前16波,后16波
A.14dbm B.15dbm C.13dbm