复制的基本规律: ●半保留复制(sem- conservative replication) ●双向复制( bidirectional replication) ●半不连续复制( semi-discontinuous replication8 复制的基本规律：  半保留复制(semi-conservative replication)  双向复制(bidirectional replication)  半不连续复制(semi-discontinuous replication)