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来源:雅诚德英语网
In breathing the chest muscles expand the rib cage and allow air to be sucked into the lungs.
呼吸时胸部肌肉使胸廓扩大让空气吸入肺部。
In breathing the chest muscles expand the rib cage and allow air to be sucked into the lungs.
呼吸时胸部肌肉使胸廓扩大让空气吸入肺部。