单项选择题 A typical application of this(71)is ADSL. It is emerging as the technology for home-and small-office Internet connectivity. It provides either 1.5 Mb/s～8 Mb/s from the network to the user and 64 Kb/s～512 Kb/s in the reverse direction depending on the distance, 12 000 or 18 000 feet.. The different speed for each direction gives it the(72)label. ADSL is designed to take advantage of the fact that video-on demand, telecommuting, and Internet access traffic are inherently asymmetrical. The user(73)a brief message up to the network and receives a ton of data coming back, either a movie or a piece of data download. Under such a scenario, low-speed traffic to the network is just fine. ADSL delivers high(74)where you need it and only uses a single copper pair. Through multiplexing, it also reserves(75)of the bandwidth for POTS.

单项选择题 某双面盘记录区的外径为12cm，内径为10cm，磁道密度为80道/cm，内圈位密度为4000bit/cm则其格式化前总存储容量为(6)字节。该磁盘共有(7)个柱面，(8)条磁道。

单项选择题 测试与排错是相互联系而性质不同的两类活动，下列Ⅰ．证实程序有错Ⅱ．修改程序错误Ⅲ．忽视对象细节Ⅳ．了解对象细节( )是排错所应具有的特征。

单项选择题 在Excel中，一个工作薄最大可有(6)上个工作表，其中每个工作表又可包含256列、(7)行。

单项选择题 ICMP的功能是(41)，采用ICMP的应用有(42)。