observant

a.观察力敏锐的

oblong, obloquy, obnoxious, obnoxiously, obnoxiousness, oboe, oboist, obscene, obscenely, obscenity, obscur, obscure, obscurely, obscurity, obsequies, obsequious, obsequiously, obsequiousness, observable, observance, observantly, observation, observation car, observation post, observatory, observe, observer, observing, obsess, obsessed, obsession, obsessional, obsessive, obsessively, obsolescence, obsolescent, obsolete, obssess, obstacle, obstacle race,