发射同步卫星时，先将卫星发射到近地圆轨道1，然后经点火使其沿椭圆轨道2运动，最后

Object-oriented analysis (OOA) is a semiformal specification technique for the object-oriented paradigm. Object-oriented analysis consists of three steps. The first step is (71) . It determines how the various results are computed by the product and presents this information in the form of a (72) . and associated scenarios. The second is (73) , which determines the classes and their attributes; Then determine the interrelationships and interaction among the classes. The last step is (74) , which determines the actions performed by or to each class or subclass and presents this information in the form of (75) .

（75）处应填（）。

A．activity diagram

B．component diagram

C．sequence diagram

D．state diagram

由出票人签发的，委托付款人在指定日期无条件支付确认的金额给收款人或出票人的票据是（）。

A.银行汇票

B.支票

C.商业汇票

D.银行本票

根据文献记载，埃及在古王国末期已有______学校，它是法老教育皇子皇孙和贵族子弟的场所。

简述商代舞蹈发展有何新成就？

副井罐笼提升系统的作用是把井下采区的矸石提升到地面，把设备下放到井下。