Which of the protocols below use TCP at the transport layer？ （Select four)A. TFTPB. SMTPC.

A.User Datagram Protocol

B.Transmission Control Protocol

C.Transport Protocol Data Unit

D.以上都不是

A.File Transfer Protocol

B.Hyper Text Transport Protocol

C.Simple Message Transfer Protocol

D.Simple Network Management Protoco

TCP/IP(Transmission Control Protoco/Internet Protocol)指传输控制协议。()

l on application layer.

A.with which

B.in which

C.on which

A.for which

B.of which

C.to which

D.in which

A.passedbytheAPtoitsconnectedswitchandthenforwardeddirectlytotheconnectedrouter，which createsanMGIDtableentry

B.passedbytheAPtotheWLANcontrollerandthenforwardedtothesourcePIM-enabledrouter，which createsanMGIDtableentry

C.passedbytheAPtotheWLANcontroller，whichcreatesanMGIDtableentrybeforeforwardingtothe directlyconnectedPIM-enabledrouter

D.passedbytheAPtoitsconnectedswitchandthenforwardedtotherendezvouspointrouter，which createsanMGIDtableentry

A.A.which

B.B.at which

C.C.in which

D.D.why

A、of which

B、for which

C、by which

D、to which

A) which B) on which C) in which D) whenever