一次群的英文

primary block

• 一次:    once
• 群:    crowd; group
• 一次群, 基群:    primary block

例句与用法

1. Information technology - telecommunications and information exchange between systems - interface connector and contact assignments for isdn primary rate access connector located at reference points s and t
   信息技术.电信和系统间信息交换.位于参照点s和t的isdn一次群速率接入的接口连接器及触电排列