Blue and orange solid line are the H I 21 cm spectra obtained by the FAST beam 1 and beam 8, respectively. The spectra werecalibrated adopting a beam efficiency of 0.85 for extended source. The red dotted lines are the spectra from the EBHIS (Winkel et al. 2016). The black solid lines are the FAST H I 21 cm spectra smoothed to have a velocity resolution similar to that of the EBHIS spectrum. To avoid overlapping, the red dotted lines and the black solid lines have been moved up by 10 and 20 K for beam 1 and beam 8, respectively.