the $1_{10}-1_{11}$ transitions of H$_2$$^{12}$CO and H$_2$$^{13}$CO were set to be 4.829660 and 4.593089 GHz, respectively (@1971ApJ...169..429T; ). 14.48848 GHz was adopted for the $2_{11}-2_{12}$ transition of H$_2$$^{12}$CO. The beam sizes are $\sim$4 arcmin at 5 GHz and $\sim$1.3 arcmin at 14.5 GHz, respectively. A Digital Backend System (DIBAS) was used for data recording (see @2016ApJ...824...136). The DIBAS mode 22 was adopted for our observations, with eight spectral windows, to cover the H$_2$$^{12}$CO and H$_2$$^{13}$CO lines simultaneously, each with 16384 channels and a bandwidth of 23.4 MHz, supplying channel widths of 0.09 km s$^{-1}$ and 0.03 km s$^{-1}$ at 5 GHz and 14.5 GHz, respectively. The system temperature was 20-30 and 30-80 K on a T$_A^*$ scale for the $1_{10}-1_{11}$ and $2_{11}-2_{12}$ transition observations, respectively. The active surface system of the primary dish and a subreflector were used to improve the aperture efficiency during our Ku-band observations. We measured an aperture efficiency of about 55 per cent (@2017MNRAS...466..4364; @2018ExpAstron..45...397) at both the C-band and Ku-band. The spectra were obtained in a position switching mode with total on source integration times of 0.3 - 3 hours and 2 - 40 mins for the $1_{10}-1_{11}$ and $2_{11}-2_{12}$ transition observations, respectively. Observational parameters 