fourer四人赛艇选手,四桨艇选手
fournum.四
four-leafed clover四叶苜蓿
four-membered ring四元环
four-channel sound四声道系统
four hundred and one(=401) 四百零一
four sub-frequency四倍频细分
four-layer complex4层复合
four-photon mixing四光子混合
four axis processing四轴联动加工
four-note doorbell四音调门铃
four-country talks四国会谈