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问题 单项选择题

已知某台活塞式空气压缩机的一级压缩比为ε=3，吸气温度为t1=20℃，在不考虑压缩机进气过程的温度升高的条件下，其多变指数n=1.59，则一级压缩终了时的排气温度为（）。

A．156℃

B．167℃

C．25℃

D．20℃

答案

参考答案：B

解析：

活塞式压缩机级时排气温度T2为：

判断题

中期票据是指具有法人资格的金融企业在银行间债券市场按照计划分期发行的，约定在一定期限还本付息的债务融资工具。（）
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Americans have four primary avenues for making friends: at work, at school, through a hobby or a (1) such as volunteer work and discussion group, or through a family or (2) .
In American culture, a job is more than the work that one performs between the hours of 9 a.m. and (3) . Work becomes a major socializing influence. Many young mothers who (4) their jobs to care for small children remark on the loneliness of their new lifestyles because they have lost their forum for (5) .
A great number of American employers recognize business social (6) and use it to build a family atmosphere on the job so that employees will feel (7) in their work environment. Some employers arrange company get-togethers in their home or at a (8) . American companies have at least one (9) annually, usually at Christmas time. Many corporations have (10) where employees and administrators alike dress (11) to play games such as baseball and volleyball.
Top American administrators often hold social gatherings (12) . Depending upon the size of the employer’s home and the number of (13) . These social gatherings may be picnics, pool parties, or (14) . If the company is large, an employer may hold what Americans call (15) . For an open house, the employer will invite his employees to come to his home (16) between 1 p.m. on a certain day. Those invited usually stay for (17) , chatting with the other guests and their host. People come and go (18) during the designated hours, and the host keeps refreshments, usually (19) or hors d’oeuvres and beverages, available for all who come. For such social gatherings, it is considered (20) the invitation unless you have an excellent reason.
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