这位记者发誓要保护她机密消息来源的身份。

The reporter vowed to protect the identity of her confidential ___source.

据一位接近调查的消息人士称，已经发现了新的证据。

According to a ___source close to the investigation, new evidence has been found.

一位政府内部人士将文件泄露给了媒体。

A government ___source leaked the document to the press.