Column density ratio CH₃OH/c-C₃H₂ in WB670 and other star-forming regions. The black points indicate the ratios measured in the seven regions of WB670 (with the exception of region 5, for which both column density estimates are upper limits). The green area corresponds to the range of values measured in local star-forming regions (Higuchi et al. 2018), and the dashed red line is the ratio measured in the outer Galaxy hot core WB789 (Shimonishi et al. 2021).