occasion

n.(重要的)场合；时机，机会

obstructionist, obstructive, obstructively, obtain, obtainable, obtrude, obtrusion, obtrusive, obtrusive-ness, obtrusively, obtuse, obtuse angle, obtusely, obtuseness, obverse, obviate, obvious, obviously, obviousness, ocarina, occasional, occasional table, occasionally, Occident, Occidental, occlude, occult, occultist, occupancy, occupant, occupation, occupational, occupied, occupier, occupy, occur, occur to, occurrence, ocean, ocean lane,