Variation of continuum (A_conti) and BEL amplitudes (A_BEL) with different inclination angles for BBHs with M_•• = 10⁹ M_⊙, ω = 0°, and e = 0.0–0.6. The two left panels show the case when only the secondary BH is active (q_L = 1 : 0), and the two right panels show the case when both the BHs are active with q_L = 1 : 1. In each panel, the points colored from dark blue to red represent the orbital eccentricity of BBHs e = 0.0–0.6, respectively.