I.Choose the single correct answer from following choose。 （1.5*20=30)[Correct checked：1。5； Other wise:0]1.Which physical media has high —speed operation and low error rate: A [］ A。Fiber optic cable［］ B。Coaxial cable［］ C。Twisted pair［］ D.Radio2 。 If no free buffers i n router ， the arriving packets will be ： B [] A.dropped［] B。queued［] C。returned[] D.marked3.Which can provides delay measurement from source to router along end-end Internet path towards destination : A ［] A。Ping［] B。Traceroute[] C。Ipconfig［］ D。Nslookup4. In TCP/IP ， which layer can make routing of datagrams from source to destination: C ［] A。Applicaion[］ B.Transport[］ C.Network[］ D。Data Link5. Web page consists of （ ） which includes several referenced objects ： A [］ A.referenced HTML—file[］ B.host HTML-file[］ C。path HTML-file［] D。base HTML—file6.What is the default persistent model in HTTP/1.1: C ［］ A。Nonpersistent HTTP［］ B。Persistent without pipelining ［] C。Persistent with pipelining［] D。Nonpersistent with pipelining7.Web server maintains no information about past client requests ， so HTTP is: B ［] A.stateful［］ B.stateless［］ C.satisfied[］ D。unsatisfied8 。 FTP client browses remote directory by sending commands over: D [］ A。connection-less[] B.free connection［] C.data connection[] D。control connection9.Which can satisfy client request without involving origin server A [］ A。Web caches［] B。Write caches［] C.TCP buffer［] D。Router buffer10 。 UDP socket identified by: B ［] A。two-tuple （source IP address, source port number)[] B.two-tuple （dest IP address， dest port number)[］ C.two-tuple (source IP address， dest port number）［］ D.two—tuple (dest IP address, source port number）11.In GBN, when...
