单项选择题
A. none
B. -600 ps/nm
C. -200 ps/nm
D. +200 ps/nm
E. +600 ps/nm
单项选择题 If the dispersion of a given fiber is 17ps/nm*km at 1550 nm and zero at 1310 nm, then what is the accumulated dispersion of an ITU wavelength after it travels 200 km?（）
多项选择题 What are three factors that limit the maximum distance of an amplified optical signal without regeneration? （）(Choose three.)
多项选择题 Click the Exhibit button. When designing a DWDM system with multiple amplified spans, a pre-amp is needed at Site B to （）. (Choose three.)