投标有效期限 meaning in English

bidding cycle

Extension of validity of bid shall normally not be requested
一般来说不应要求延长投标有效期限。
Bidder shall have the right to refuse to grant such an extension of validity of bid without forfeit their bid bond
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。
Those who is willing to extend the validity of their bid shall be neither required nor permit to modify their bid
对同意延长其投标有效期限的投标人，既不要求也不允许他们修改其投标。