which are configured for the specific requirements of the organization. (40)A LAN is generally limited to the size of a department or an organization and often (41)The three main types of LAN are topology, transmission media and medium (42)Most wide area networks, such as the PSTN, use a mesh topology (43) The four topologies in common use are star, bu (44)Twisted pair, coaxial cable and optical fibre are the three main types of transmission medium used for LANs (45) techniques have been adopted for use of the medium access control in the LANS (46) Two is used to control multiple-access networks (47)Control token is another way of controlling access to a shared transmission medium 6. Decide whether the following statements are True or False (48)A LAN (Local area data networks) is a group of computers and the network devices connected together usually within the different buildings (×) (49)LAN may be used to interconnect computer-based equipment distributed around a factory or hospital complex (50)A LAN is generally limited to the size of a department or an organization and often consists of 2 to 100 devices (51) Most wide area networks, such as the PStn, not use a mesh (sometimes referred to as a network) topology (52)With LANS, the limited physical separation of the subscriber DTEs allows simpler topologies to be used (53)The four topologies in common use are star, router, ring and hub (54)Three techniques have been adopted for use of the medium access control in the LANS (55)Control token is the only way of controlling access to a shared transmission medium 7. Translate and analyze the following sentences (56) By definition, the connections must be high-speed and relatively inexpensive(e.g. token ring or Ethernet) 句子组成: by definition为独立结构,也可以放在句后 翻译:通过定义可知,这种连接冖定是高速并且相对廉价的(如ε令牌网和以太网)s (57)They are configured for the specific requirements of the organization 句子组成:for引导介词短语修饰coniμure,而of引导的名词作后置定语修饰 翻译:它们根据组织的各种特殊需要来配置 (58)Since all the equipment is located within a single establishment, however, LANS are normally installed and maintained by the organization 句子组成:两个分句由转折词 however连接,后半句使用了被动语态 翻译:虽然所有设备限制在一个单一的设施里,但局域网通常由团体安裝和维 (59) LANS consist of carefully selected groups of components(hardware and software)which are___ configured for the specific requirements of the organization._. (40) A LAN is generally limited to the size of a department or an organization and often consists of___2_ to __100 vices. (41) The three main types of LAN are _topology_, _transmission media_ and _medium access control methods_. (42) Most wide area networks, such as the PSTN, use _a mesh__ topology. (43) The four topologies in common use are star_, __bus__ , _ring__ and __hub__. (44) _Twisted pair_, _coaxial cable_ and _optical fibre__ are the three main types of transmission medium used for LANs. (45) ______ techniques have been adopted for use of the medium access control in the LANs. (46) __Two__ is used to control multiple-access networks. (47) _Control token___ is another way of controlling access to a shared transmission medium . 6. Decide whether the following statements are True or False. (48) A LAN (Local area data networks) is a group of computers and the network devices connected together usually within the different buildings. (× ) (49) LAN may be used to interconnect computer-based equipment distributed around a factory or hospital complex. (× ) (50) A LAN is generally limited to the size of a department or an organization and often consists of 2 to 100 devices. (√ ) (51) Most wide area networks, such as the PSTN, not use a mesh (sometimes referred to as a network) topology. (× ) (52) With LANs, the limited physical separation of the subscriber DTEs allows simpler topologies to be used. (√ ) (53) The four topologies in common use are star, router, ring and hub. (× ) (54) Three techniques have been adopted for use of the medium access control in the LANs. (× ) (55) Control token is the only way of controlling access to a shared transmission medium. (× ) 7. Translate and analyze the following sentences. (56) By definition, the connections must be high-speed and relatively inexpensive (e.g. token ring or Ethernet). 句子组成：by definition 为独立结构，也可以放在句后 翻译：_通过定义可知，这种连接一定是高速并且相对廉价的（如：令牌网和以太网）。 (57) They are configured for the specific requirements of the organization. 句子组成：for 引导介词短语修饰 configure，而 of 引导的名词作后置定语修饰 requirements 翻译：__它们根据组织的各种特殊需要来配置。__ (58) Since all the equipment is located within a single establishment, however, LANs are normally installed and maintained by the organization. 句子组成：_两个分句由转折词 however 连接，后半句使用了被动语态______ 翻译：虽然所有设备限制在一个单一的设施里，但局域网通常由团体安装和维护。 (59) LANs consist of carefully selected groups of components (hardware and software)