四川邮电职业技术学院教案专用纸 4. it can carry voice in one direction at a time only n one direction意思是在同一个方向上, at a time意思是一次. 5. this would require on the order of2×10:8 links.意即:这将需 要有2×10:8数量级的链路.句中 on the order of…意为“在…的数量级上” 6. Designers have found it convenient to organize these nodes int a hierarchy or tree topology, consisting of five classes of switching centers or nodes.设计人员发现将这些节点有机的连结,组成了由五级交换 中心或节点构成的层次结构或树状拓扑.句中的it代替由动词不定式to organize引出的短语; consisting of…为现在分词短语,修饰 a hierarchy or tree topology作定语; to organize…inte 为短语动词 7. Subscribers connect directly to an end office, which must perform the same functions as a pBx.用户直接连到端局,端局必须执行 与PB相同的功能.句中 which引导的是非限制性定语从句:the same…as…意为:与…相同的…;PBX是 Private Branch Exchanges的缩 略词,即“用户小交换机” 8. The remaining centers simply serve the function of concentrating traffic so as to reduce transmission facility requirements.其余的中心仅提供集中通 信业务量的功能,以减少对传输设备的要求句中 so as to:为的是,以便, 以致 9. In addition to the five classes of switching centers listed above. the network is augmented with additional switching nodes called tandem switches In addition to意思是除什么之外, listed above是过去分词短语 作后置定语,意思是以上所列出的; called tandem switches也是过去 分词短语作后置定语,修饰 switching nodes 10. reflecting the fact that, at any given time, only a fraction of the subscribers will be engaged in external calls that引导的是同位语从句,作 the fact的同位语 in意为”进行” 11. The structure depicted in Fig 22: 1 was referred to as having a tree topology.图22-1所画的结构称为树状拓扑.句中 to refer to sb.(sth.)as…为短语动词,意为“称某人(某物)为…”.此句使用了该 短语动词的被动形式,也可译为主动句“我们称图22-1所画的结构为树状拓 扑” 12. High-usage trunks are used for direct connection between switching enters with high volumes of internode traffic re used for表示用于什么方面,with引起的介词短语作后 置定语,修饰 switching centers表示有大量的节点间的业务量的 3. The calling subscribers end office will determine if a direct trunk exists to the called end office.主叫用户的端局要确定是否有一 条直达中继线连到被叫端局.句中 the calling subscriber意为主叫用户;the called end office意为被叫端局; calling是现在分词,表示主动; called 是过去分词,表示被动,请看下面的例子 a moving film 一部感动人的影片 moved audience 受感动的观众 developing countries发展中国家 developed countries 发达国家 14. If not, or if that trunk is fully loaded the call is routed up to a toll center Page 5 of 6 Teaching Plan of English for Telecommunications UnitI四川邮电职业技术学院教案专用纸 Page 5 of 6 Teaching Plan of English for Telecommunications Unit14 4.it can carry voice in one direction at a time only. in one direction 意思是在同一个方向上, at a time 意思是一次. 5. this would require on the order of 2×10:8links. 意即:这将需 要有 2×10:8 数量级的链路.句中 on the order of …意为“在…的数量级上”. 6. Designers have found it convenient to organize these nodes into a hierarchy or tree topology, consisting of five classes of switching centers or nodes. 设计人员发现将这些节点有机的连结，组成了由五级交换 中心或节点构成的层次结构或树状拓扑.句中的 it 代替由动词不定式 to organize 引出的短语；consisting of …为现在分词短语，修饰 a hierarchy or tree topology 作定语；to organize…into… 为短语动词. 7. Subscribers connect directly to an end office, which must perform the same functions as a PBX. 用户直接连到端局，端局必须执行 与 PBX 相同的功能.句中 which 引导的是非限制性定语从句；the same…as… 意为:与…相同的…；PBX 是 Private Branch Exchanges 的缩 略词，即“用户小交换机”. 8. The remaining centers simply serve the function of concentrating traffic so as to reduce transmission facility requirements. 其余的中心仅提供集中通 信业务量的功能，以减少对传输设备的要求.句中 so as to :为的是，以便， 以致 9. In addition to the five classes of switching centers listed above, the network is augmented with additional switching nodes called tandem switches. In addition to 意思是除什么之外, listed above 是过去分词短语 作后置定语, 意思是以上所列出的; called tandem switches 也是过去 分词短语作后置定语,修饰 switching nodes. 10. reflecting the fact that, at any given time, only a fraction of the subscribers will be engaged in external calls. that 引导的是同位语从句, 作 the fact 的同位语. be engaged in 意为”进行” 11. The structure depicted in Fig.22:1 was referred to as having a tree topology. 图 22-1 所画的结构称为树状拓扑.句中 to refer to sb.(sth.) as … 为短语动词，意为“称某人(某物)为…”.此句使用了该 短语动词的被动形式，也可译为主动句“我们称图 22-1 所画的结构为树状拓 扑”. 12. High-usage trunks are used for direct connection between switching centers with high volumes of internode traffic. are used for 表示用于什么方面, with 引起的 介词短语作后 置定语,修饰 switching centers 表示有大量的节点间的业务量的. 13. The calling subscriber's end office will determine if a direct trunk exists to the called end office. 主叫用户的端局要确定是否有一 条直达中继线连到被叫端局.句中 the calling subscriber 意为主叫用户；the called end office 意为被叫端局；calling 是现在分词，表示主动；called 是过去分词，表示被动，请看下面的例子: a moving film 一部感动人的影片 a moved audience 受感动的观众 developing countries 发展中国家 developed countries 发达国家 14. If not, or if that trunk is fully loaded, the call is routed up to a toll center