This letter is an annex to that report.

这封信是那份报告的附件。

Then he discovered the annex to the party.

接着，他发现聚会还有附属部分。

The annex to the source code, only your reference!

附件是源代码，仅供大家参考！

This proposed language appears in the draft Annex to this Report.

这个建议的表达方式出现在这个报告的附件草案中。

You may find an answer to your question in the annex to the report.

你可以从报告的附件中找到你问题的答案。