Low-velocity (Δ_ν ≤ 1.2 km s⁻¹ ) SiO (5−4) emission for MDC220 (left) and MDC684 (right). The integrated velocity ranges of the contours are presented at the top-right corner. The black contour levels are (−3, 3, 6, 9) × σ, with σ = 0.13 Jy beam⁻¹ km s⁻¹, for both MDCs. The black and white crosses represent dust condensations identified by Cao et al. (2021). The grayscale maps represent 1.37 mm continuum emission. The scale bar is presented in the bottom-right corner. The synthesized beam is shown in the bottom-left corner.