渔夫从口袋里掏出一把大折刀来割绳子。

The fisherman pulled out a ___jackknife from his pocket to cut the rope.

游泳运动员在比赛中做了一个漂亮的屈体跳水动作。

The swimmer did a perfect ___jackknife during the competition.

由于刹车失灵，拖车突然发生了甩尾。

The trailer ___jackknifes suddenly due to brake failure.