o ringobjective functionobjective lensochroma lagopusoil in placeoil resistanceoil shaleoil shale reservesolephilicoligomeroligomerizationoliveomega endone side clingonlineopacityopaqueopen moldingopen tack timeopen weaveoperating arenaoperating costoperating lineoperating pointoperatoroptical fiberoptical lossoptical modulationoptical propertiesoptical susceptibilityoptical windowoptimumoptimum cureorange peelorb weborbitalorgandieorganismorganoclayorganometallic compoundorganomontmorilloniteorganophileorganosiliconorientationorientational briefringenceorientedorificeorthoorthogonal arraysoscillator
