您要查找的是不是：
- 二纤双向MSP环Dual-fiber two-way MSP ring
- 二纤双向复用环two-fiber MS shared protection ring
- 二纤双向复用段自愈保护环two-fiber two-way multiplex section self-recovery and protection loop
- 二two
- SDH环网由二纤环扩容升级至四纤环的方案探讨Strategies to upgrade SDH MS-Spring from two fibers to four fibers
- 两纤双向复用段保护环Two fiber bi-directional multiplexing segment protection ring
- 实用的单纤双向传输模数信号混传系统A Mixing Transmission System of Practical Single Fiber Duplex Analog and Digital Signal
- 二号2nd day of the month
- 二楼second floor
- 圆环traffic circle
- 周二Tuesday
- 二次adratic quadrate
- 二等second-class
- 外环outer ring
- 纤体slim
- 大二学生sophister
- 手环wrist strap
- 小二young waiter in a wineshop or an inn
- 内环inner belt
- 磁环magnetic ring
