adj.第一等的,第一流的;
例句:
She wore a one-piece white bathing costume.
她穿着白色的连体泳衣。
He described the referendum as a one-horse race.
他称这次全民公决是一场胜负分明的比赛。
It was just a one-off; it won't happen again.
这事绝无仅有;不会再发生了。