the filamentary structures and the W33 complex). In Figure \[fig9\]c, we present the overlay of the NVSS 1.4 GHz radio continuum contours on the color-composite image produced using the C$^{18}$O maps at \[29.6, 43.3\] and \[47.2, 60.2\] km s$^{-1}$. Both the color-composite images allow us to infer the overlapping zones of the two clouds at \[47.2, 60.2\] and \[29.6, 43.3\] km s$^{-1}$, where the early phase of SF, dust clumps as well as H[ii]{} regions are evident. Furthermore, in the color-composite images, a spatial fit of the intensity-depression region and the intensity-enhancement region is observed toward the W33 complex (see also Figure \[fig10\]). In the direction of the W33 complex, an intensity-enhancement is found in the molecular intensity maps at \[29.6, 43.3\] km s$^{-1}$ (see Figures \[fig10\]a and \[fig10\]b), while an intensity-depression region or cavity-like feature is observed in the molecular intensity maps at \[47.2, 60.2\] km s$^{-1}$ (see Figures \[fig10\]c and \[fig10\]d). The locations of W33 A (G012.90$-$0.24, G012.90$-$0.26), W33 Main (G012.81$-$0.19), and three O4-7I stars [see IDs \#7, 8, and 23 in @messineo15] are seen toward the areas of the spatial fit of the cavity and the intensity-enhancement region. However, the filament “fs1" and W33 B are found 