！expire的前缀是ex和词根是pire，v. 到期，失效死亡呼气，吐气（任期）届满
He is planning another tour abroad， yet his passport will expire at the end of this month.他计划再次出国旅行，但他的护照将于本月底到期。
5bn program of grants to fund new affordable housing， set to expire in 2015， is unlikely to be extended beyond then.
