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。

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。

He bound the box with a piece of string.

他用绳子把箱子捆好。

The kidnapper strangled the child with a piece of string.

绑票的人用一根绳子把这孩子勒死了。

You are wearing a piece of string!

你用的是一根绳子！