A. They make remote functions appear local, transparent to the user
B. They transfer files to and from remote nodes
C. They make the transport layer independent
D. They allow multiple applications to share the same connection to the network
9) What is WinSock (什么是Wi n S o c k )?
A. A version of sockets for the Microsoft Windows platform
B. Sockets on BSD UNIX
C. A session layer API commonly considered to be its own protocol
D. A network layer service for Microsoft Wi n d o w s
10) What does TLI do (TLI的作用是什么)?