根據(jù)下面的文字資料回答 71～75 題 In the following essay，each blank has four choices．Choose the most suitable one from the four choices and write down in the answer sheet．A（ 1 ）is basically an end point of a communication link between two applications.Sockets that extend over a network connect two or more applications running on separate computer sat tached to the network．Asocket（ 2 ）twoaddresses：（ 3 ）．Sockets providea （ 4 ）communication channel between one or more systems.There are stream and datagram sockets separately using TCP and（ 5 ）．

第6題：文中（ 1 ）處正確的答案是（ ）。

A．program

B．UDP

C．socket

D．TCP

CSocket是兩個應(yīng)用之間的聯(lián)系接口。Socket使網(wǎng)絡(luò)中不同的計算機(jī)之間的應(yīng)用能夠聯(lián)系在一起。一個Socket有兩個地址：端口號和IP地址。Socket提供了在多個系統(tǒng)中全雙工通信的方式。TCP在Socket傳遞的是字符流，而UDP傳遞的是數(shù)據(jù)報。