（）is not a physical wall but a flow virtual data to protect the computer network.
举一反三
- （）is not a physical wall， but a lot of virtual data to protect the computer network.
- The WDM transmission network consists of three layers: Physical Layer、Data Link Layer and Network Layer.
- _____ cards are used to connect a computer to a network. A: MiniDC B: Network adapter C: Battery D: AC adapter
- The Internet is the （）network of computers all over the world. A: virtual B: only C: physical D: first
- Which OSI layer handles flow control, data segmentation, and reliability A: Application B: Physical C: Transport D: Data Link