回答：expiration的动词是expire，意思是“v. 到期，失效；死亡；呼气，吐气；（任期）届满”。
例句
①When does your driving licence expire?
你的驾照什么时候到期？
②However, most of these contracts expire this month.
不过，这些合同大部分在本月到期。
③This was due to expire at the end of the present Congress.
这项任命在本届国会届满时将到期。
