根据前驱图，P2进程需要等待P1进程的通知，故需要利用P(S1)操作测试P1进程是否运行完，所以空①应填P(S1)，P2进程运行结束需要利用V操作分别通知P3、P4进程，由于P3进程执行前已经用P(S2)，所以空②应填V(S2)。
根据前驱图，P3进程运行结束需要利用两个V操作分别通知P4、P5进程，故空③应为两个V操作；又由于P4执行前需要等待进程P2、P3的结果，需要2个P操作，而P4进程的程序中执行前只有1个P操作，故空④应为1个P操作。采用排除法，对于试题(49)的选项A、选项B、选项C和选项D中，只有选项A满足条件。
根据前驱图P4、P5进程执行完都需要通知P6进程，P6进程运行前执行了P(S6)和P(S7)，而P5进程执行完后执行了V(S7)，故P4进程应该执行V(S6)，即空⑤应填V(S6)。又因为P5进程开始运行前必须等待P3进程的通知，需要用P(S5)操作测试P3进程是否运行完。故空⑥应填写P(S5)。
Designing the data storage architecture is an important activity in system design. There are two main types of data storage formats： files and databases. Files are electronic of data that have been optimized to perform a particular transaction. There are several types of files that differ in the way they are used to support an application. （ ） store core information that is important to the business and , more specifically , to the application , such as order information or customer mailing information. （请作答此空） contain static values , such as a list of valid codes or the names of cities . Typically, the list is used for validation. A database is a collection of groupings of information that are related to each other in some way. There are many different types of databases that exist on the market today. （ ） is given to those databases which are based on older , sometimes outdated technology that is seldom used to develop new applications . （ ） are collections of records that are related to each other through pointers In relational database , （ ） can be used in ensuring that values linking the tables together through the primary and foreign keys are valid and correctly synchronized.
The service measurement metrics do not include （ ）。
The （ ） is the primary point of contact for users when there is a service disruption, for Service Requests, or even for some categories of Request for Change.
（ ） is pre-authorized by Change Management that has an accepted and established procedure to provide a specific change requirement.
The Service Design stage of the lifecycle starts with （ ） and ends with the development of a service solution designed to meet the documented needs of the business.
