【简答题】Many people have to work at weekends. Some people do not mind, others think it is terrible. One man thinks that working at weekends can be __21__. He is George Smith. Mr. Smith works in an office, in ...
【多选题】请选择下列那些金融工具(金融产品)属于直接融资工具?
【简答题】回火的目的是什么?工件淬火后为什么要及时回火? 回火的目的是消除和减小内应力,稳定组织,调整性能,以获得较好的强度和韧性配合。淬火钢的组织主要由马氏体和少量残余奥氏体组成____,其内部存在很大的内应力,脆性大,韧性低,一般不能直接使用,如不及时消除,将会引起工件的变形,甚至开裂。
【单选题】People will find this valley a beautiful place __________ they may spend their weekends.
【简答题】During the week days,they are luckily busy office people; but on weekends,they are just a brood of(一窝)stay home animals.A recent survey shows that office workers in China prefer quiet and easy ways to...
【判断题】增压器工作叶轮的作用是将涡轮的机械能转换成为空气的动能和压能。()
【简答题】汽轮机叶轮的作用是什么?运行中的叶轮会受到哪些力的作用?