occasionally (adv.) occasional (adj.) occasion (n.) occasion n.场合；时机；理由；机会；盛大场面vt.引起；致使ocarina (n.) oc- obviousness n. 显而易见；明显；显著性obvious (adj.) obvious adj. 明显的；显著的；平淡无奇的obviation (n.) obviate (v.) obverse (adj.) obtuse (adj.) obtund (v.) obtrusive (adj.) obtrusion (n.) obtrude (v.) obtains vt.获得；得到vi.流行；通用；存在obtaining v. （尤指经努力）获得；通用，继续存在（obtain 的现在分词）obtainer vt.获得；得到vi.流行；通用；存在