如下图所示，一架飞机在北半球自东向西飞，飞机左侧是高压，可判断
A．顺风飞行
B．逆风飞行
C．风从北侧吹来
D．风从南侧吹来
答案：B
在进行城市污水系统的工程设计时，常用到变化系数的概念，下列关于污水量变化系数的表述中，不正确的是（）。
A．日变化系数
B．时变化系数
C．总变化系数Kx＝KdKh
D．变化系数随污水量的大小而不同，污水流量越大，其变化幅度越小
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) .
A. activity diagram B. component diagram C. sequence diagram D. state diagram
