In doubles, during the delivery of service (Law 9.2, 9.3), the partners may take up any positions within their respective courts, which do not unsight the opposing server or receiver.是什么意思_In doubles, during the delivery of service (Law 9.2, 9.3), the partners may take up any positions within their respective courts, which do not unsight the opposing server or receiver.在线翻译_英语_读音_用法_例句