A pitfall trap can be any small container placed in the ground with the top level with the surrounding surface and filled with a preservative.

陷阱可以是任何放置在地面上的小容器，其顶部与周围的表面齐平，并装满防腐剂。

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They add flavour and act as a preservative but they can be present even in foods you don't expect or are labelled in ways that you don't recognise.

它们可以添加风味，并作为防腐剂，但是它们可以存在于你没有预料到的食品中，或者以你不能识别的方式贴上标签。

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In high doses methanol can make people go blind or even die because the body converts it to formaldehyde, a poison used as a preservative in some laboratories.

甲醇摄入量过高会致盲或致死，因为人的身体会把它转化成甲醛——在实验室里作为防腐剂使用的有毒物质。

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