单项选择题
A. fiber loss
B. OSNR level
C. post amplification
D. index of reflection
E. index of refraction
F. power post amplification budget
单项选择题 Click the Exhibit button. Which type of multiplexer is shown in the exhibit？（）
多项选择题 Whatarethreefactorsthatlimitthemaximumdistanceofanamplifiedopticalsignalwithoutregeneration？（）
单项选择题 Ifthedispersionofagivenfiberis17ps/nm*kmat1550nmandzeroat1310nm，thenwhatistheaccumulateddispersionofanITUwavelengthafterittravels200km？（）