Summary of pebble and gas properties. The pebble surface density (brown) and maximum pebble size (gray) are obtained from multiple-wavelength analysis. The gas surface densities are obtained from modeling based on ALMA observations of CO isotopologues. The blue curves we present here are those where a CO abundance of n(CO)/n(H₂) = 10⁻⁴ is assumed, which shall be taken as the lower limit of the total gas density, as significant CO depletion could exist (e.g., Zhang et al. 2021). The peaks of continuum rings and the minima of continuum gaps are indicated by solid and dashed vertical lines respectively.