關於Jacks的意思和用法的提問

A: Jumping jacks are physical exercises where you wave your arms overhead and jump your legs out to your side in time.

A: It's a form of warm-up exercises :#

A: Jumping jacks is an type of callisthenic exercise. A person performs the exercise by jumping from a standing position with legs together and arms at the sides to a position with the legs apart and the arms over the head.

I believe the name comes from the fact that there's a resemblance to a child's toy called a "jack"--see pictures.

A: i think she’s jack’s mom