Line profiles of HO 1₁₁–0₀₀ (black) and C¹⁸O 9–8 (red) towardour 19 sources. The vertical green line denotes the C¹⁸O velocity in Table 3. For IRAS 18151, we show H₂O 1₁₁–0₀₀ instead of the HO line which is not detected. For IRAS 18151, IRAS 16272 and IRAS 05358, the blue dotted spectrum is ¹³CO 10–9 as C¹⁸ O is weak or noisy. The dip in the G10.47 spectrum at V_LSR > 80 km s⁻¹ is an artifact from the image sideband.