我的后背有点痒，你能帮我挠一下吗？

My back itches, can you help me by ___scratching it?

他用硬币刮掉了彩票上的涂层。

He used a coin to ___scratch off the coating on the lottery ticket.

我听到猫在门上的抓挠声。

I heard the ___scratching of a cat on the door.

由于家庭原因，他不得不退出比赛。

He had to ___withdraw from the race because of family issues.

他在笔记本上随手画了个草图。

He ___scratched a rough sketch in his notebook.