ordinary level (also O level)

(formerly in British education) examination of basic standard in the General Certificate of Education （旧时英国普通教育文凭的）普通级考试.

orchestra pit, orchestra stalls (US orchestra), orchestral, orchestrate, orchestration, orchid, ordain, ordeal, order, order-book, order-form, order-paper, ordered, ordering, orderliness, orderly, ordinal, ordinance, ordinarily, ordinary, ordinary seaman, ordination, ordnance, Ordnance Survey, ordure, ore, organ, organ-grinder, organ-loft, organdie (US also organdy), organic, organic chemistry, organically, organically-grown, organisation, organise, organism, organist, organization, organization, organisation,