A.FSY跟蹤GPR B.RBD跟蹤LCI C.RBD跟蹤GPR D.FSY跟蹤LCI
A.10 B.20 C.40 D.60
A.數(shù)據(jù)鏈路層 B.傳輸層 C.網(wǎng)絡(luò)層 D.物理層