[填空题]Each year some 4 trillion e-mails are sent worldwide from about 600 million electronic mailboxes. In 1995, employees sent three e-mails per day and received five. E-mail usage has jumped mom than six fold, with employees now sending an{{U}} (36) {{/U}}of 20 e-mails and receiving 30 each day. During March and April 2001, Rogen International{{U}} (37) {{/U}}the first study on the{{U}} (38) {{/U}}of e-mail and face-to-face communication in the work place. More than 1,400 senior-and middle-level executives{{U}} (39) {{/U}}in the international survey. They said that despite popular myth, e-mail has not{{U}} (40) {{/U}}the amount of face-to-face communication{{U}} (41) {{/U}}at work. While executives are spending an average 120 minutes a day receiving, checking,{{U}} (42) {{/U}}and sending e-mails, they are also still spending 130 minutes a day in formal and informal face-to-face meetings. The message from the research is clear. Business leaders should{{U}} (43) {{/U}}th