A.齒面剝落 B.齒面點蝕 C.齒面裂紋 D.斷齒
A.上邊帶頻 B.下邊帶頻 C.側(cè)邊帶頻 D.中邊帶頻
A.dBN稍小于dBC B.dBN等于dBc C.dBN稍大于dBC D.dBN遠大于dBc