A.若干數(shù)據(jù)庫,一個通信子網(wǎng),一組通信協(xié)議 B.若干主機,電話網(wǎng),大量終端 C.若干主機,電話網(wǎng),一組通信協(xié)議 D.若干主機,一個通信子網(wǎng),一組通信協(xié)議
A.查找 B.替換 C.清除 D.打印