the bernoulli-euler problem of the misaddressed letters
Related Translations:
信封: envelope 短语和例子拆开信封 open an envelope; 防潮信封 a moisture-proof envelope; 撕开信封 tear open a letter; 用不封口的信封邮寄 post in an open envelope; 将信折好放进信封。 fold the letter and put it in an envelope. 请附上写明
