所谓犯罪构成是指刑法规定的犯罪行为所应当具备的一切客观和主观要件的总和。其中，犯罪的目的和动机属于( )

A．犯罪主体

B．犯罪客体

C．犯罪的主观方面

D．犯罪的客观方面

Networks can be interconnected by different devices. In the physical layer, networks can be connected by (11) 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 (12) ,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 (13) network layer, the router may be able to translate between the packer 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 (14) . As an example, gateways between Internet e-mail and X.400 e-mail must (15) the e-mail message and change various header fields.

13（）

A.special

B.dependent

C.similar

D.dissimilar