Networks can be interconnected by different devices. In the physical layer, networks can be connected by （66） or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept （67） , 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 networks. If two networks have （68） 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 two transport connections. Finally, in the application layer, application gateways translate message （69） . As an example, gateways between Internet e-mail and X.400 e-mail must （70） the e-mail message and change various header fields.

（75）处填（）。

A．detailed

B．outlined

C．total

D．complete

各级党组织和广大党员要增强（），坚持把对党绝对忠诚作为根本政治要求和最重要的政治纪律，始终在思想上政治上行动上同党中央保持高度一致。

A.政治意识

B.大局意识

C.核心意识

D.看齐意识