jump index

例句：

1. 1. The jump index is ameasure of how quickly an animal can changeits position in the air.
   跳跃指数是衡量动物在空中改变位置速度的指标。
2. 2. Thejump index has been used to study thebehavior of birds during migration.
   跳跃指数被用来研究鸟类迁徙期间的行为。
3. 3. The jump indexis often used as a reference point formeasuring the performance of athletes.
   跳跃指数常被用作衡量运动员表现的参考点。