2010年软件水平考试系统分析员精选练习题

　　十、从供选择的答案中，选出应填入下面叙述中　?　内的最确切的解答，把相应编号写在答卷的对应栏内。

　　由两个相同的计算机单元组成的双工系统，λ和μ分别表示计算机单元的故障率和修复率。用P2、P1和P0以及P2′、P1′和P0′分别表示系统在某一时刻以及下一时刻有两个、一个和零个单元正常工作的概率。若假定两个完好单元不会同时损坏且只有一个修理工进行维修，则系统的状态方程可写成：

 

　　当系统处于稳定状态时，与不稳定状态相比，还满足条件　B　。此时系统无故障运行的概率为　C　，系统能有效运行的概率为　D　，系统完全失效的概率为　E　。

　　供选择的答案

　　十一、从供选择的答案中，选出应填入下面英语文句中 ? 内的正确答案，把编号写在答卷的对应栏内。

　　OOP languages that create objects, such as A and B , are beginning to take hold as viable tools for programmers. To effectively reuse objects, programmers need a place to store them such as an ODBMS or an RDBMS with objectoriented extensions.

　　Databases that handle object data not only let user store and retrieve C data, but let them store objects created by OOP languages, to facilitate rapid software development and reuse, and let them D new multimedia applications combining multiple data types.

　　RDBMS vendors have developed new extensions to existing DB technology to accommodate the most common forms of E data.

　　供选择的答案

　　A~E：①PASCAL ②BASIC ③C ④C++

　　⑤FORTRAN ⑥SMALLTALK ⑦numeric

　　⑧nonalphanumeric ⑨structured ⑩unstructured

　　⑾to build ⑿build ⒀to be built

　　⒁built