.

D persistent connection without pipelining

44. In HTTP request messages, the request line has three fields, there are .

A the method field, the URL field and the HTTP version field B the method, the connection and URL field

C the user-agent, the method and HTTP version field D the user-agent, the URL and the HTTP version field

45. In the header lines of HTTP request message, if the field of Connection is close, it specifies . A the host on which object resides B what type of the user agent

C that the browser wants the server to close the connection after sending the requested object

D which language can the browser receive

46. In HTTP response message, if the status code is 404, it means . A request succeeded and the information is returned in the response B requested object has been permanently moved

C the requested HTTP protocol version is not supported by the server D the requested document does not exist on this server

47. is a network entity that satisfies HTTP requests on the behalf of an origin Web server.

A proxy server B local server C DNS server D Web server 48. In the following four options about web cache, which one is not correct?

.

.

A A web cache is both a server and a client at the same time. B A web cache is purchased and installed by an ISP.

C A web cache can raise the response time for a client request.

D A web cache can reduce traffic on an institution’s access link to the Internet. 49. The request message in the conditional GET must include the header line.

A Last-Modified B Last-Referenced C If-Modified-Since D If –Referenced-Since

50. FTP uses two parallel connections to transfer a file, they are . A TCP and UDP connection

B connection with pipelining and without pipelining C control an data connection

D client-server and browser-server connection

51. In FTP commands, which one is used to ask the server to send back a list of all files in the current remote directory?

A USER B PASS C LIST D RETR

52. In the Internet mail system, allow users to read, reply to, forward, save and compose message.

A User agents B mail servers C SMTP D TCP 53. The two key MIME headers for supporting multimedia are . A Content-Type and MIME-Version

B Content-Type and Content-Transfer-Encoding C Content-Transfer-Encoding and MIME-Version

.

.

D MIME-Version and MIME-Type

54. For Internet mail, the mail access protocol is used to .

A transfer mail from the recipient’s mail server to the recipient’s user agent B transfer mail from the sender’s mail server to the recipient’s mail server C translate the mail from the sender’s mail server D translate the mail into the recipient’s mail server

55. POP3 progresses through three phases, which they are . A authorization, translation and transaction B authorization, translation and update C authorization, transaction and update D translation, transaction and update

56. In the following four services, which one can not provide by DNS? A Host aliasing B Mail server aliasing C translate hostname to IP addresses D translate MAC addresses to IP addresses

57. There are three classes of DNS servers, there are . A root DNS server, top-level domain DNS server and local DNS server B root DNS server, top-level domain DNS server and authoritative DNS server C root DNS server, local DNS server and authoritative DNS server D root DNS server, local DNS server and top-level domain DNS server 58. In the following four options about POP3, which one is not correct? A The user agent employed only three commands: List, Retr and Quit B The server does not carry state information across POP3 sessions

.

.

C The port number is 110

D The POP3 protocol does not provide any means for a user to create remote folders and assign messages to folders.

59. A resource record in DNS distributed database is a four-tuple, which field can be ignored?(p132) A Name B Value C Type D TTL 60. In the following four options about DNS resource record, which one is correct? A The meaning of Name and Value depend on Type. B The meaning of Value and Type depend on Name.

C If Type=A, then Name is a domain and Value is the IP address for the hostname. D If Type=MX, then Name is domain and Value is the IP address for the hostname. 61. In the following four options about DNS messages, which one is not correct? A There are only two kinds of DNS message.(p133) B Both query and reply message have the same format. C The header section in DNS message has 12 bytes.

D The authority section contains the resource records for the same that was originally queried.

62. In DNS message, contains information about the query that is being made.(p133)

A authority section B question section C answer section D additional section

63. There are three techniques are employed in most any P2P file-sharing systems, which one is not include? （p144）

.