雅思词汇

oar oasis oath obedient object objection objective obligation obligatory oblige obliging oblique oblivious oblong obnoxious obscene obscure observance observatory observe obsess obsession obsolete obstacle obstinate obstruct obvious occasion occupy occur occurrence odd odds odor odyssey offence offend offer offset offshore offspring omen ominous omit on once oncoming one ongoing onlooker onset opaque opening opinion opponent opportunity oppose opposite oppress opt optical optimism optimum option optional orbit orchard orchestra ordeal orderly ore organ organism oriental orientate origin original originate ornament orthodox oscillate ostensible ostentation otherwise oust out outbreak outcast outcome outcry outdated outdo outfit outlaw outlet outline outlying output outrageous outright outset outskirts outspoken outstrip outweigh oval ovation overall overcome overdue overflow overhaul overhear overlap overlook override overrun oversee overt overtake overthrow overture overwhelm overwrought owe ownership oxide