  Shocks are abundant in star-forming regions, and are often related with star
formation. In our previous observations toward 100 starless clump candidates
(SCCs) in the Galaxy, a sample of 34 SCCs associated with shocks is identified.
In this work, we perform mapping observations of the SiO 2-1, 3-2, HC$_3$N
10-9, HCO$^+$ 1-0, H$^{13}$CO$^+$ 1-0, and H41$\alpha$ lines toward 9 out of
the detected sources by using IRAM 30-m radio telescope to study the origins of
the shocks in the SCCs. We find shocks in three sources (BGPS 3110, 3114, and
3118) are produced by collisions between the expanding ionized gas and ambient
molecular gas, instead of by the star formation activity inside SCCs. On the
other hand, shocks in the other six sources are related to star formation
activity of SCCs. The signatures of protostellar outflows are clearly shown in
the molecular lines toward BGPS 4029, 4472, 5064. Comparing our results with
the previous ALMA observations performed in the same region, the shocks in BGPS
3686 and 5114 are also likely to be due to protostellar activity. The origin of
shock in BGPS 5243 is still unclear although some features in the SiO spectra
imply the presence of protostellar activity.
