下面有两个错别字的一项是   [ ]

A．怡然自得    睡眼惺松    顶礼莫拜    奄奄一息

B．阿谀奉承    万恶不赦    遍稽群籍    浩瀚无垠

C．走头无路    销声匿迹    引颈受戮    乐此不疲

D．吹毛求疵    周到如砥    山崩地裂    鳞次栉比

For each blank, choose the best answer from the four choices and write down on the answer sheet.
(71) is a professional organization of individuals in multiple professions which focuses on effort on lower-layer protocols.
(72) 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.
(73) functions with two layers of protocols. It can connect networks of different, speeds and can be adapted to an environment as it expands.

A. MAC address and IP address B. MAC address and port address
C. E-mail address and IP addressD. port number and IP address

A socket is composed of two addresses: (74) .Heterogeneous network environments consist of computer systems from (75) vendors that run different operating systems and communication protocols.