问题描述：
英语翻译
This kind of consideration is valid when the exchange of promises between two parties will be carried out later.
In contrary,executed consideration is not valid until the exchange of consideration between two parties is carried out.
This kind of consideration is valid when the exchange of promises between two parties will be carried out later.
In contrary,executed consideration is not valid until the exchange of consideration between two parties is carried out.
问题解答：
我来补答展开全文阅读