将用户计算机与远程主机连接起来，将本地的输入送给远程计算机，在远程计算机上运行程序，最终把相应的输出传送到本地机器上显示，这种服务使用的协议是(63)协议。如果用户计算机已经与网络物理相连，为了登录到远程主机—上访问网络资源，必须有(64)。

(58)

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Applications put computers to practical business(67), but below the(68)it's the heart of an operating system-the kernel-that provides the technical wizardry to juggle multiple program, connect to networks and store(69).

In　C　language,(75)　are　used　to　create　variables　and　are　grouped　at　the　top　of　a　gram　block.

One　important　difference　is　that　an　ActiveX　control　must　be(74)　for　a　specific　platform,　　while　an　applet　is　platform-independent.

(73)　is　a　channel's　capacity　which　directly　reflects　the　data　transfer　rate　of　the　channel.

DBMS　will"　manage　"the　stored　data　items　and　assemble　the　needed　items　from　the(72)　database　in　response　to　the　queries　of　those　who　aren't　programmers.

On　a(71)　memory　system,　the　logical　memory　space　available　to　the　program　is　totally　independent　of　the　physical　memory　space.