Observation of CH A(sup 2) ->X(sup 2pi) and B(sup 2(sigma)) -> X Emissions in Gas-Phase Collisions of Fast O ((sup 3)P) Atoms with AcetyleneOptical emissions in single-collision, beam-beam reactions of fast (3-22 eV translational energy) 0((sup 3) P) atoms with C (sub 2) H (sub 2) have been measured in the wavelength range 300-850 nm.