An acceptance once given ca ot be revoked unle the offeror co ents. 除非要约人同意，承诺一经做出即不得撤回。
The death of the offeree or offeror may terminate an offer. 受要约人或要约人的死亡将可能使要约终止。
If the withdrawal reaches the offeror before or at the same time as the acceptance would have become effective. 公约规定，在接受送达发盘人之前，受盘人将撤回接受的通知送达发盘人，或两者同时送达，则接受可以撤回。
