會對折的那把刀
這一家只有一個成員，就是那個實物：其他所有用法都是從它的動作借出去的。
noun · B2
A knife with a blade that folds down into its handle, so that it can be carried safely in a pocket or a bag and opened when it is needed.
折疊小刀
核心畫面
Picture a pocket knife closing: the blade swings on its hinge until the two halves lie flat against each other, with a click. It is a fast, sharp fold at one single point. One way to hold jack-knife is to keep that closing knife in view — first the object itself, then anything long that folds the same way, whether it is a in the air, a body on a mat, or a truck on ice.
可以想成一把折疊刀正在合起來：刀身沿著轉軸轉，直到兩半貼在一起，喀的一聲。那是一個又快又利的折，而且只折在一個點上。…更多收起
可以想成一把折疊刀正在合起來：刀身沿著轉軸轉，直到兩半貼在一起，喀的一聲。那是一個又快又利的折，而且只折在一個點上。jack-knife 的各種意思，一種想法是都站在那把刀旁邊——先是那把刀本身，再來是所有會用同樣方式折起來的長東西：空中的跳水選手、墊子上的身體、結冰路面上的連結車。Three branches
身體折成一把刀
把刀換成人，動作原封不動：在中間用力一折，兩半合起來。
verb · C1
To bend sharply in the middle, the way a folding knife closes — used about a person's body, an animal, or anything long that folds at one point.
像折刀一樣猛地對折
車子在路上折起來
車頭和拖車之間那個接點，就是刀的轉軸；輪胎一失去抓地力，車子就沿著它闔上。
verb · B2
If a long vehicle made of two joined parts jack-knifes, the back part slides out of control and swings round towards the front, so the whole vehicle folds into a sharp V shape.
（連結車）打滑折起