求翻译：A contract is an agreement by which two parties mutually promise to buy or sell some products. An executed contract is one that has been fully carried out by both parties. An executory contract is one that is yet to be performed. In practice, some informal contracts may be reached orally. This is understandable, but may lead to unfortunate consequences. A reasonable exporter should at least insist on strict observance of the legal requirements in case of orders that are not routine transactions.是什么意思？

待解决 悬赏分：1 - 离问题结束还有