Someone had played a trick on her, stretched a piece of string at the top of those steps.

有人对她搞恶作剧，在那些台阶的顶部拉了一根绳子。

《柯林斯英汉双解大词典》

I need a piece of string to parcel this up.

我需要一根绳子来把这东西捆起来。

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Originally they were round pieces of metal with a hole in the center, so that a piece of string could keep them together.

最初它们是圆圆的金属片，中间有一个洞，这样一根绳子就可以把它们串在一起。

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To keep himself awake as he flew east during the long night, Post tied a piece of string to one finger.

VOA: special.2009.03.18

Why not own a creature you can stroke and cuddle and tease with a piece of string?

BBC: Exotic pets: Why do Americans keep dangerous animals?

While he waits, a chain-smoking captain, Salih Yilmaz, busies himself with a plastic bottle and a piece of string, fishing for calamari to serve in his restaurant.

BBC: The perfect trip: Turkey

Early research involved a colleague lying in a deckchair in the night-time open air with a piece of string to measure the meteors, while he observed electromagnetic signals on a cathode-ray tube in a nearby hut.

ECONOMIST: Bernard Lovell | The