在文件系统中，文件的不同物理结构有不同的优缺点。在下列文件的物理结构中(18)结构不具有直接读写文件任意一个记录的能力。

(72)

(71)

(70)

(69)

Because　Web　servers　are　platform.　and　application(71)they　can　send　or　request　data　from　legacy　or　external　applications　including　databases.　All　replies,　　once　converted　into(72)mark-up　language,　can　then　be　transmitted　to　a(73).　Used　in　this　way,　　Intranets　can(74)lower　desktop　support　costs,　easy　links　with　legacy　applications　and　databases　and,(75)all,　　ease　of　use.

(75)is　not　a　programming　language.

A　small　network　may　only　connect　two　computers　inside　a　home　to　share,　a　single　printer　and　Internet(74).

There　are　several　applications　called　Web(73)that　make　it　easy　to　access　the　World　Wide　Web.　two　of　the　most　popular　being　Netscape　Navigator　and　Microsoft'　s　Internet　Explorer.

Users　also　need(71)systems　to　help　them　explore　the　web　and　discover　interesting　data　sources　and　interfaces　that　support　different　query　and　search　paradigms.

The　smallest　physical　units　on　a　hard　disk　are　called(72).