[] happening only once一次性的◆The package includes a one-time $300 tax cut.这套方案包括 300 元的一次性减税。◆a one-time charge/cost/gain/loss一次性收费/成本/收益/损失SYNone-off ➡exceptional former原先的;从前的;一度的◆Companies such as BP have been buying up one-time competitors.诸如英国石油公司这样的公司一直在收购原先的竞争对手。