Movement balance in track and field is dynamic equilibrium. With active characteristics, human balance differs greatly from the balance of rigid body.

田径运动中的平衡是动态平衡，活体特征使人体平衡与刚体平衡有本质区别。

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Meanwhile, the basket has the non-rigid structure, thereby being suitable for active and playful children and not hurting human body due to the problems such as collision.

同时，由于其为非刚性结构，较适宜活泼好动的儿童使用，不会因碰撞等问题，对人体造成任何伤害。

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