【正文】 接人 C. CableModem 接人 D. PPP/SLIP 方式 68. 以下屬于 10BASEF 定義的光纖規(guī)范是 (A )。 A． 2400bps B． 9600bps C． 19200bps D． 38400bps 72. (B )屬于傳統(tǒng)局域網(wǎng)。 A． IP 和 UDP B． SMTP 和 Tel C． TCP 和 UDP D． RARP 和 ARP 76. 下列功能描述中屬于網(wǎng)絡(luò)層功能的是 ( D )。 A. B. . 25. 261 C. 202. 96. 96. 218 D. 81. 下列關(guān)于數(shù)字?jǐn)?shù)據(jù)網(wǎng) DDN 描述不正確的是 ( B )。 D．比交換型網(wǎng)絡(luò)具有更高的透明性。 A．星型網(wǎng) B．廣播式網(wǎng)絡(luò) C．分布式網(wǎng)絡(luò) D．總線型 85. ( D )屬于數(shù)據(jù)鏈路層的功能。 A．完成不同網(wǎng)絡(luò)層協(xié)議之間的轉(zhuǎn)換 B．把網(wǎng)絡(luò)中的服務(wù)器連接到網(wǎng)絡(luò)上 C．接口控制 D．減少局域網(wǎng)中的數(shù)據(jù)發(fā)送沖突的發(fā)生 89. 在進(jìn)程的執(zhí)行過程中，以下進(jìn)程狀態(tài)之間的轉(zhuǎn)換屬于進(jìn)程主動行為的是 ( B )。 A．頻分復(fù)用 B．波分復(fù)用 C．時分復(fù)用 D．碼分復(fù)用 93. 分組交換的顯著特點(diǎn)是 ( D )。 (1)如果信道空閑，則發(fā)送； (2)如果信道有載波，則繼續(xù)對其進(jìn)行偵聽，一旦空閑，立即發(fā)送； (3)如果發(fā)送中檢測到碰撞，則停止自己的正常發(fā)送，轉(zhuǎn)而發(fā)送一個短暫的干擾信號以強(qiáng)化碰撞信號，使 LAN 上所有站都能知道出現(xiàn)了碰撞； (4)發(fā)送干擾信號之后，退避一個隨機(jī)時間，再重新嘗試發(fā)送。 3． 簡述什么是協(xié)議。 局域網(wǎng)具有以下主要特點(diǎn)： 網(wǎng)絡(luò)覆蓋的地理范圍有限：通常在幾十米到幾千米的范圍內(nèi)。 配置簡單：共享式的局域網(wǎng)或交換式局域網(wǎng)的一般應(yīng)用通常不需要任何配置就可直接進(jìn)行網(wǎng)絡(luò)通信，因此對網(wǎng)絡(luò)使用者的技術(shù)水平的要求較低。 6． 簡述路由器的主要作用。 首先， Inter 是一個開放的網(wǎng)絡(luò)。 9． 簡述數(shù)據(jù)通信的特點(diǎn) 1)數(shù)據(jù)通信實(shí)現(xiàn)的是機(jī)與機(jī)之間的通信。 5)數(shù)據(jù)通信具有靈活的接口能力。由于存在著建鏈和拆鏈時間，傳輸效率不高。這種方式的優(yōu)點(diǎn)是傳輸效率高，缺點(diǎn)是可靠性差，因?yàn)橐坏┚€路質(zhì)量不好，到達(dá)收端的分組不全會影響收端的正常排序。 傳信率與碼元速率之間滿足下列公式 : Rb=RBlog2M 其中 Rb 為傳信率， RB 為碼元速率， M 為進(jìn)制。在一定程度上減輕 IP 地址匱乏的危機(jī)，提高 IP 地址的分配和利用的效率，同時縮小了廣播網(wǎng)絡(luò)的規(guī)模。 答：和傳統(tǒng)的電話電報(bào)通信相比，數(shù)據(jù)通信具有如下特點(diǎn)： ① 數(shù)據(jù)通信實(shí)現(xiàn)的是機(jī)與機(jī)之間的通信。 ③ 傳輸速率高，要求接續(xù)和傳輸響應(yīng)的時間快。 專業(yè)好文檔 14 3． 某一數(shù)字信號的碼元速率為 4800Baud，試問當(dāng)采用四進(jìn)制或二進(jìn)制傳輸時，其信息傳輸速率各為多少 ? 當(dāng)采用 四 進(jìn)制傳輸時 ， 信息傳輸速率 =4800* 2log 22=4800*2=9600bps 當(dāng)采用二進(jìn)制傳輸時 ， 信息傳輸速率 =4800* 2log 21=4800*1=4800bps 4． 填寫下列表格中空白的部分。外線輸入端接電話入戶線，如有分機(jī)應(yīng)在分線器前接入濾波器；電話信號輸出接電話專業(yè)好文檔 15 機(jī)，可以在上網(wǎng)的同時進(jìn)行電話通話。 2)檢查是否安裝了相關(guān)的協(xié)議，網(wǎng)卡驅(qū)動是否正常工作?；卮鹨韵聠栴}： (1)根據(jù)提供的硬件，兩臺 PC 機(jī)直聯(lián)應(yīng)制作哪種連接線，兩端各采用什么線序？ (2)簡述該網(wǎng)線的制作步驟。 步驟 水晶頭的連接與壓線：取水晶頭，將有金屬銅觸 點(diǎn)的一面向上，按照從左至右為 18 引腳的線序?qū)㈦p絞線插入水晶頭的線槽中。跳接線制作成功后，正常測試的燈序?yàn)? 2。s celebrations said he wanted to meet Ivory Coast international Toure to discuss his plaint. CSKA general director Roman Babaev says the matter has been exaggerated by the Ivorian and the British media. Blatter, 77, said: It has been decided by the Fifa congress that it is a nonsense for racism to be dealt with with fines. You can always find money from somebody to pay them. It is a nonsense to have matches played without spectators because it is against the spirit of football and against the visiting team. It is all nonsense. We can do something better to fight racism and discrimination. This is one of the villains we have today in our game. But it is only with harsh sanctions that racism and discrimination can be washed out of football. The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。s about how he felt and I would like to speak to him first to find out what his experience was. Uefa has opened disciplinary proceedings against CSKA for the racist behaviour of their fans during City39。s plaint. In a statement the Russian side added: We found no racist insults from fans of CSKA. Baumgartner the disappointing news: Mission aborted. The supersonic descent could happen as early as Sunda. The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our daytoday weather lives. It will climb higher than the tip of Mount Everest ( miles/ kilometers), drifting even higher than the cruising altitude of mercial airliners ( miles/ kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence. The balloon will slowly drift to the edge of space at 120,000 feet ( 專業(yè)好文檔 17 Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform. Below, the Earth bees the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, h