有效期限

• useful-life
• valid period
• unexpired term
• expiry date
• life span
• period of validity

例句

1. 一般来说不应要求延长投标有效期限。
   Extension of validity of bid shall normally not be requested.
2. 投标人有权拒绝延长投标有效期限并不会因此而失掉其投标保证金。
   Bidder shall have the right to refuse to grant such an extension of validity of bid without forfeit their bid bond.
3. 还有，有效期限？
   And the expiration date?