oscillation

n.波动；振动；振荡

orphan, orphanage, orris-root, orth(o)-, orthodontic, orthodontics, orthodontist, orthodox, orthodoxy, orthographic (also orthographical), orthographically, orthography, orthopaedic (also orthopedic), orthopaedics (also orthopedics), orthopaedist (also orthopedist), ortolan, oryx, OS, Oscar, oscillate, oscillator, oscillograph, oscilloscope, osier, osmosis, osmotic, osprey, osseous, ossification, ossified, ossify, ossilate, oste(o)-, ostensible, ostensibly, ostentation, ostentatious, ostentatiously, osteo-arthritis, osteopath,