He received a threatening letter.

他收到一封恐吓信。

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A McCain campaign office received a threatening letter containing an unidentified powder.

麦凯恩竞选办公司收到了一封含有未经确认粉末的威胁性。

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A McCain campaign office received a threatening letter containing an unidentified powder. Authorities say the substance wasn't dangerous, and they already have a suspect.

麦凯恩的竞选办公室收到内涵不明粉末的信函的威胁，官方表示这些物质没有危险，而且他们已经确定了嫌犯。

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Dorner claimed Williams was harassing him and sent a threatening letter to his home.

NPR: Court File: LA Ex-Cop Was Disturbed, Self-Obsessed

He said she had done a "smell test" of the threatening letter, telling him it burned her nose a bit.

NPR: Experts: Ricin Like That In Letters Easy To Make

Another variety of threatening letter was sent to taxpayers under audit.

FORBES: You have the right to be terrified