Molecular Clouds Associated with {H \small{II}} regions and Candidates
  within l = 106.65$^\circ$ to 109.50$^\circ$ and b = ${-}$1.85$^\circ$ to
  0.95$^\circ$
  We present a large-scale simultaneous survey of the CO isotopologues ($\rm
{}^{12}{CO}$, $\rm{}^{13}{CO}$, and $\rm{C}{}^{18}{O}$) J = 1 ${-}$ 0 line
emission toward the Galactic plane region of l = 106.65$^\circ$ to
109.50$^\circ$ and b = ${-}$1.85$^\circ$ to 0.95$^\circ$ using the Purple
Mountain Observatory 13.7 m millimeter-wavelength telescope. Except for the
molecular gas in the solar neighborhood, the emission from the molecular gas in
this region is concentrated in the velocity range of [${-}$60, ${-}$35] $\rm
km~s^{-1}$. The gas in the region can be divided into four clouds, with mass in
the range of $\sim$10$^{3}$ to 10$^{4}$\,${M_{\sun}}$. We have identified 25
filaments based on the $\rm {}^{13}{CO}$ data. The median excitation
temperature, length, line mass, line width, and virial parameter of the
filaments are 10.89 K, 8.49 pc, 146.11 ${M}_{\odot}~ \rm pc^{-1}$, 1.01 $\rm
km~s^{-1}$, and 3.14, respectively. Among these filaments, eight have virial
parameters of less than 2, suggesting that they are gravitationally bound and
can lead to star formation. Nineteen {H \small {II}} regions or candidates have
previously been found in the region and we investigate the relationships
between these {H \small {II}} regions/candidates and surrounding molecular
clouds in detail. Using morphology similarity and radial velocity consistency
between {H \small {II}} regions/candidates and molecular clouds as evidence for
association, and raised temperature and velocity broadening as signatures of
interaction, we propose that 12 {H \small {II}} regions/candidates are
associated with their surrounding molecular clouds. In the case of the {H
\small {II}} region of S142, the energy of the {H \small {II}} region is
sufficient to maintain the turbulence in the surrounding molecular gas.
