单项选择题
A. They are both regions of lowest loss.
B. They are both regions of low reflections.
C. They are both regions of low index of refraction.
D. They are both regions of low chromatic dispersion.
E. They are both regions of low Polarization Mode Dispersion (PMD).
单项选择题 What is an advantage of an externally modulated laser over a directly modulated laser?（）
单项选择题 What is the difference between the transmitted power and the sensitivity of the receiver?（）
多项选择题 Which three technologies are used to reduce chromatic dispersion accumulation in fiber-optic transmission systems? （）(Choose three.)