The chief function of the muscles of the back when one is erect is to resist gravity.
一个站立的人的肩肌的主要功能是抵抗重力。
Keep your posture straight and erect. Your head should be up, your back straight, and shoulders level.
保持您的姿势挺而直，抬起头，挺直腰，双肩水平。
Keep your posture straight and erect. Your head should be up, your back straight, and shoulders level.
保持您的姿势挺而直，抬起头，挺直腰，双肩水平。
应用推荐