5us，协同业务的同步精度为3us（15kz）、0.7us（30khz）、0.19us（120khz）（）

合并单元在外部同步时钟信号消失后，至少能在内继续满足4us的同步精度要求 TD-LTE系统对时钟的要求很高，要求精度小区3us，为了保证空口时钟同步，设计使用GPS作为每个基站的基准时钟，GPS时钟精度为 She told us that her brother ______ the Army for 3 years. SDH帧结构以us为帧同步周期（） Not only ____ strict with us, but also ____ for us. We hope you could _____ us a special discount of 3 on orders. us [5sE:kEs] 调试超声波检测仪时,测得t0=5us,已知某测点声距L=40cm,仪器显示声时为105us,则超声波在混凝土中传播的声速为（） India exports US$150 billion IT products to the US（） We ________ a parent to care for us, to forgive us our errors, and to save us from our childish mistakes. Professor Wu told us that by the end of the year he _______ here for 3 years. We（）your letter of Nov.3 asking us to make a quotation. Their sudden attack made us more () of the danger around us Not only ______ prepare lunch for us, but also _______ clothes for us. Not only（ ）us light, but it also gives us heat. Though the teacher is strict _____ us, she is good to us. [ ] will it take us to fly to Hainan and will the trip to Hainan cost us? 3.4NEWS2 1: Russia and Germany.|The US and Germany.|The US and Russia.|The US and the UK. 示电路中，已知：US = 15 V，当IS 多带带作用时，3W电阻中电流I1?= 2 A，那么 当IS、US 共同作用时，2W电阻中电流I是( ? ? ? ? ? ? ? ? ? ? ? ? ? )。 ? 图中 R1=6Ω，R2=4Ω，R3=3Ω，US1=12V，US2=24V。则电流I1=2A。()