某旅行社主要经营入境旅游业务，根据《旅行社条例》规定，应当缴纳质量保证金( )元。
A．10万 B．20万 C．30万 D．120万
参考答案：B
330MW电动给水泵与电动给水泵前置泵共用一个（）。
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. more thanB. than C. that D. which
