发送附件时，邮件系统会自动添加合适的MIME头信息。

The email system automatically adds the appropriate ___MIME headers when sending attachments.

这位演员通过无声的模仿表演讲述了一个感人的故事。

The actor told a touching story through a silent ___mime performance.

他擅长模仿名人的说话方式，常常逗大家笑。

He is good at ___mimicking famous people's way of speaking, which always makes everyone laugh.