UML是一种面向对象的同一建模语言。它包括10种图，其中，用例图展示了外部参与者与系统内用例之间的连接。UML的外部参与者是指 (47) ，用例可以用 (48) 图来描述。 (49) 指明了对象所有可能的状态以及状态之间的迁移。协作图描述了协作的 (50) 之间的交互和链接。
（48）处填（）。
A．类
B．状态
C．活动
D．协作
参考答案：C
| 阅读理解。 | ||||||
Mike's Calenda
| ||||||
| 1.On which day does Mike have to study the whole day? | ||||||
| A. Thursday B. Sunday C. Tuesday D. Friday | ||||||
| 2.What does Mike do over the weekend? | ||||||
| A. Go to school. B. Practice soccer. C. He can do anything he likes. D. Take a test. | ||||||
| 3.How many days does Mike have to go to school in a week? | ||||||
| A. Seven B. Five C. Six D. Four | ||||||
| 4.When does Mike go to Jenny's party? | ||||||
| A. On Tuesday B. On Sunday C. On Friday D. On Monday | ||||||
| 5.What is Mike doing on Thursday evening? | ||||||
| A. Visiting Uncle Li B. Watching TV C. Helping his parents D. Studying for a test |