填空题 “窗体布局窗口”客户区域的左上角代表桌面坐标的（）。

单项选择题 I/O系统主要有(24)、(25)和(26)三种方式来与主机交换数据。其中(24)主要用软件方法来实现，CPU的效率低；(25)要有硬件和软件两部分来实现，它利用专门的电路向CPU中的控制器发出I/O服务请求，控制器则(27)转入执行相应的服务程序；(26)主要由硬件来实现，此时高速外设和内存之间进行数据交换丝(28)。

单项选择题 For each blank, choose the best answer from the four choices and write down on the answer sheet.(21)is a six bytes OSI layer 2 address which is burned into every networking evice that provides its unique identity for point to point communication.(22)is a professional organization of individuals in multiple professions which focuses on effort on lower-layer protocols.(23)functions with two layers of protocols. It can connect networks of different speeds and can be adapted to an environment as it expands.(24)is the popular LAN developed under the direction of the IEEE802.5.(25)is the popular backbone technology for transmitting information at high speed with a high level of fault tolerance which is developed under the direction of ANSI.

单项选择题 SDLC was invented by IBM to replace the older Bisynchronous protocol for wide area connections between IBM equipment. A varietion of the(71)protocol called NRM is essentially the same as SDLC. SDLC is(72) protocol like HDLC, Frame. Relay or X.25.An SDLC network is made up of(73)that controls all communications, and(74). It is capable of(75)operation, but almost all practical applications are strictly half duplex.

单项选择题 Multipurpose Internet Mail Extension (MIME) is a(46)document messaging standard in the Internet enviroment, with MIME, users can send(47)Email messages that include audio, video, graph-ices, and text to any other user of a TCP/IP network. Richtext information can also be(48)into messages. It defines the fonts, formats, and(49)features of a document so the document can be easily(50)on many different types of systems.