Continuum-subtracted FIFI-LS spectra of far-IR emission lines detected toward DR21 Main (see Table 2). Each row corresponds to the emission integrated in the boxes of 16.5^′′ × 50^′′ each along the DR21 Main outflow, with position numbers increasing from east to west (see Figs. C.1 and 2). The spectra of [O I] 63.18 μm, [O I] 145.53 μm, and [C II] 157.74 μm are divided by factors of 6, 2, and 3, respectively.