In the following essay,each blank has four choices．Choose the best answer and writedown on the answer sheet．
Communicating via E—mail is by far the most common Internet activity．You can (71) with anyone in the world who has an Internet address or E—mail (72) with a systemconnection to the Intemet．All you need is (73) the Internet and an E—mail program．Two ofthe most widely used E．mail programs are Microsoft’s (74) and Netscape’S Navigator．Atypical E．mail message has three basic (75) ：header，message，and signature·
A．packets
B．elements
C．frames
D．cells
参考答案：B
解析：通过E-mail进行联系通常是Internet上应用最广泛的活动。你可以与世界上任何一个拥有Internet地址或一个连接在Internet的系统上的E-mail账户进行通信。你所需要做的只是访问Internet和一个E-mail程序。应用最广泛的两个E-mail程序是Microsoft’sOutlook Express和Netscape’s Navigator。一个典型的E-mail消息包括三个基本元素：邮件头、消息和签名。