单词本：be a fly on the wall

在Allen Kelly关于产品负责人描述中，写到： Being a fly on the wall can provide useful insights to the Product Manager. 上下文大致意思是说产品经理跟销售去见客户，在旁边看看，也可以了解洞察客户需求。 (Kelly 2019)

be a fly on the wall 确实很形象，一只苍蝇静静地趴在墙上偷偷看着听着，肯定能获得不少机密消息。所以，这个词组的意思在一旁静静观察。

比如：I would love to be a fly on the wall in Kimi’s house when he finds out his wife bought a new car without telling him.

另外，fly-on-the-wall “墙上的苍蝇”多用于指代“观察型纪录片”，此类纪录片一般如实反应片中人物的真实生活，不会因为拍摄而影响人物的行为。

比如：It was a fly-on-the-wall documentary series, seen by man y as the precursor to reality television. 这是一部观察型纪录片，被很多人认为是真人秀电视节目的先驱。

还比如最近英国新国王 William 登基。他的儿子 William 王子则推出了直播节目：“Prince William: Fly on the Wall”：

​Exciting news for fans of the British Royal Family: Prince William, the Duke of Cambridge, is set to feature in a new ITV documentary series called “Prince William: Fly on the Wall” releasing on 7th May.

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