perpetualadj.永久的;永恒的;一再往复的
perpetual exchange长兑
perpetual shiplock三峡永久船闸
perpetual trailing长跟
perpetual calendar万年历
perpetual pavement永久性路面
perpetual dividend永续股利
perpetual nuisance永久的损害
perpetual pavements长寿命路面
perpetual provision永久性条款
perpetual raspberry四季树莓