expiry 专八

What is the expiry date on your library novel?

你从国书馆借的小说书哪一天到期?

A surveillance audit is carried out once a year within the three-year validity period and recertification audit will be conducted at the expiry of the three-year period.

在三年有效期内每年进行一审核，三年到期进行再认证审核。