noun 下载 🔗分享 气动邮递系统，气动信件 The pneumatic postal system in Paris (abolished 1984), or a letter sent by this system. Examples : ""Before email, Parisians could quickly send urgent messages across the city using pneumatiques, special letters transported through underground tubes by compressed air." " 在电子邮件出现之前，巴黎人可以使用气动信件，即通过压缩空气在地下管道中传输的特殊信件，来快速地在城市中传递紧急信息。 communication system technology machine writing history 与AI对话词汇游戏阅读练习
