obstinate

a.固执的；难克服的

observatory, observe, observer, observing, obsess, obsessed, obsession, obsessional, obsessive, obsessively, obsolescence, obsolescent, obsolete, obssess, obstacle, obstacle race, obstetric, obstetrician, obstetrics, obstinacy, obstinately, obstreperous, obstreperously, obstreperousness, obstruct, obstruction, obstructionism, obstructionist, obstructive, obstructively, obtain, obtainable, obtrude, obtrusion, obtrusive, obtrusive-ness, obtrusively, obtuse, obtuse angle, obtusely,