英语翻译
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.
答
当双方之间的承诺之后将实行改变时,这种考虑是有效的.
与之相反的,知道双方的考虑发生改变之后,考虑执行才会有效.