(51) is a six bytes OSI layer 2 address which is burned into every networking device that provides its unique identity for point to point communication.
(52) is a professional organization of individuals in multiple professions which focuses on effort on lower-layer protocols.
(53) functions with two layers of protocols. It can connect networks of different speeds and can be adapted to an environment as it expands.
(54) is the popular LAN developed under the direction of the IEEE802.5.
(55) 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.

A．The hub

B．The bridge

C．The router

D．The proxy

患者，男性。1个月前到南方出差，近 1周来发作寒战，隔日发作1次，无发热，伴呕吐，腹泻，神昏不语，舌淡红苔白厚腻，脉弦。此治疗以下列何方为宜

A．清瘴汤
B．连朴饮
C．鳖甲煎丸
D．加味不换金正气散
E．八珍汤