Spectra of the eight spectral windows analysed in this study. Panels a), b), e), and f) present data obtained from the observations reported by Liu et al. (Project 2021.1.00311.S), whereas panels c), d), g), and h) correspond to the dataset acquired by Fuller et al. (Project 2015.1.01312.S). Each spectrum was extracted from a beam-size region centred at the peak of the continuum emission. Molecular transitions were identified using the SDAS database.