PV maps of ¹³CO (1–0) gas of the R1 region. Panels (a) and (b) are l-PV and b-PV maps, respectively. Three prominent gas components, namely, N68a, N68b, and N68c, are highlighted by blue, red, and cyan dashed boxes, respectively. The projection of bubble N68 is depicted by a white dashed ellipse. The bridge features connecting N68a and N68b are marked by magenta arrows, which correspond to the locations of p2 and p6 in Figure 7, respectively.