opal

n.蛋白石

onshore, onside, onslaught, onto, onto (also on to), ontological, ontology, onus, onward, onward(s), onyx, oodles, oomph, ooze, op, op (also Op), op art, op-ed, opacity, opague, opalescence, opalescent, opaque, opaquely, opaqueness, OPEC, open, open an account, open cheque, open day, open letter, open out, open prison, open question, open sandwich, open to, open up, open verdict, open vowel, open-air,