A.≤5% B.≤10% C.≤12% D.≤15%
A.不響鈴 B.響短鈴 C.長(zhǎng)鳴鈴 D.無(wú)回鈴音
A.2Mbit/s B.1Mbit/s C.3Mbit/s D.5Mbit/s