软件的维护并不只是修正错误。为了满足用户提出的增加新功能、修改现有功能及一般性的改进要求和建议，需要进行(55)，它是软件维护工作的主要部分。

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)