①礼仪；外交礼节a system of fixed rules and formal behaviour used at official meetings, usually between governments
②条约草案；议定书；（协议或条约的）附件the first or original version of an agreement, especially a treaty between countries, etc.; an extra part added to an agreement or treaty
③（数据传输的）协议a set of rules that control the way data is sent between computers
④科学实验计划；医疗方案a plan for performing a scientific experiment or medical treatment
吉果0412
