scrape的过去式怎么变化

　　例句：

　　I scraped the side of my car on the wall.

　　我车的一侧被墙刮了。

　　How did you get that scrape on your knee?

　　你膝盖上的擦伤是怎么弄的？

　　She fell and scraped her knee.

　　她摔了一跤，把膝盖蹭破了。