three laws三个规律threenum.三n.三；三个adj.三个的three-cylinder water pump三缸水泵three-level understanding贾岛three hundred and sixty one(=361) 三百六十一three spoonfuls of medicine三匙药three hundred and fifty one(=351) 三百五十一three-dimensional effectsn.三维效应three electrode single tube三电极单管three benzene molecular tap三苯环分子带three-dimentional imaging三维显像three instantaneous centres三瞬心