敕答书

例句：

1. 1. He sent a letter to his friend in Beijing.
   他给在北京的朋友寄了一封信。
2. 2. She received a missive from her sister.
   她收到了姐姐的来信。
3. 3. The letter contained important information about the project.
   信里包含了关于这个项目的重要信息。