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 determines 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) .

（72）处填（）。

A．component diagram

B．sequence diagram

C．interactive Diagram

D．use-case diagram

在新民主主义革命时期，不同的时代有不同的革命精神。下列革命精神按出现的先后顺序排序正确的一组是

①五四精神②延安精神③井冈山精神④长征精神[ ]

A．①②③④

B．①③②④

C．①③④②

D．①④③②