需求分析的任务是借助于当前系统的物理模型导出目标系统的逻辑模型，解决目标系统“做什么”的问题。(52)并不是需求分析的实现步骤之一。

To　accommodate　the　longest　path　allowed　by　802.3,　the　slot　time　has　been　set　to　512　bit　times,　or(75).

Every　host　and　muter　on　the　Internet　has　an　IP　address,which　encodes　its(69).

When　you　choose　a　command　name　that　is　followed　by　"…"　on　menu,　a(72)box　appears　in　which　you　provide　more　information.

The　Pentium　includes　hardware　for　both　segmentation　and　paging.　Both　mechanisms　can　be　disabled,　allowing　the　user　to　choose　from　four　distinct　views　of　memory.　Now　the　most　frequently　used　view(such　as　UNIX　System　V)is(67).

The　typical　firewall　consists　of　two　packet　filters　and　a(an)(68).

In　a　computer,　which　of　the　following　is　the　longest　period?(66).

(73)

(71)

(72)

(70)