The contract comes into existence when the acceptance is received by the offerer except when the post is used.
一旦要约人收到承诺，该合同便正式订立，但使用邮件送达方式的情况除外。
2
Is the bank, post office serve time that outside serving a place to be opposite, announces the bank and post office acceptance to the public or a kind of aeriform contract?
银行、邮局等服务场所对外公布的服务时间是银行和邮局等对公众的承诺还是一种无形的合同？
3
So, if anyone wishes to withdraw an offer by post he must make sure that it reaches the acceptor before or at the same time as the acceptance is posted.