1、He applied the sprag to the back wheel of his bicycle to prevent it from rolling down the hill.
他在自行车后轮上装上了夹子来防止它下山滚动。

2、The truck driver used a sprag to chock the wheels of the semi-trailer while it was parked.
卡车司机在停车时使用夹子固定半挂车的车轮。