关于交换机，下面说法中错误的是（）。

A、以太网交换机根据MAC地址进行交换

B、帧中继交换机根据虚电路号DLCI进行交换

C、三层交换机根据网络层地址进行转发，并根据MAC地址进行交换

D、ATM交换机根据虚电路标识和MAC地址进行交换

Networks can be interconnected by different devices．In the physical layer，networks can be connected by (64) or Hubs, which just move the bits from one network to an identical net-work. One layer up we find bridgas and swiehes, which operate at data link layer. They can accept (65) , examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two netwoks. If two networks have (66) network layer, the router may be able to translate between the packet formats. In the transport layer we find transport gateway, which can interface between the two transport connections. Finally, in the application layer, application gateways translate message

(67) . As an example, gateways between Internet e-mail and X.400 e-mail must (68) the e-mail message and change various header fields.

66（）

A．special

B．dependent

C．similar

D．dissimilar