thread pitch

例句：

1. 1. She carefully threaded the needle through the fabric.
   她小心翼翼地把针穿过布料。
2. 2.The old woman used to thread her needle by candlelight.
   这位老妇人过去常常在烛光下穿针引线。
3. 3. The thread of their relationship was frayed after years of separation.
   他们的关系因为多年的分离而变得脆弱。