中共七届二中全会在党的建设方面所做出的重大贡献是： [ ]

A、妥善处理了党内存在的分岐和矛盾

B、确立了毛 * * 思想为党的指导思想

C、要求全党抵制腐朽思想的侵蚀，继续保持党的优良作风

D、清算了"左"的和右的错误，达到空前的团结和统一

The major problem with E-mail is that it is (71) easy to use that people can become (72) with messages (73) they can possibly answer in a day. In addition, mail boxes require some management to (74) messages or archive those that might be required later. Senders don’t always know about your E-mail backlog and often send (75) messages.

A．manage

B．save

C．backup

D．dispose of