Spectrum comparison of HDO, CH₃OH, ¹³CH₃OH, CH₂DOH, and CH₃OD toward selected sources in Orion BN/KL with a similar resolution of about 3′′. The SMA ¹³CH₃OH line (Tang, priv. comm.) is plotted in blue for a synthesized beam of . The CH₃OH line is plotted in red for a synthesized beam of . The HDO (thick black lines), CH₃OD (thin black lines), and CH₂DOH (magenta) lines are plotted for a synthesized beam of . Dotted lines indicate a V_LSR of 8 km s^-1. Note that the spectrum intensities of CH₃OH and CH₂DOH are multiplied by 2. Clearly, the spectra of methanol isotopologs have narrow line widths compared with those of HDO.