Please enter a valid date.请输入有效的日期。重点词汇valid ['v?l?d]adj.（法律上）有效的；（正式）认可的；符合逻辑的；合理的Web正当的；有根据的；正确的扩展例句1.At a minimum, the existence of a contract would serve as an authorization check; without a valid contract, the service cannot be invoked.最低限度，合同的存在将起到授权核查的作用；如果没有有效的合同，将不能调用服务。2.Once the connectio
