【評論主題】23. For older people, doing exercises in swimming pools is especially helpful _____ the buoyant effe

【評論內容】A) because of:屬「介係詞」，...

【評論主題】23. For older people, doing exercises in swimming pools is especially helpful _____ the buoyant effe

【評論內容】A) because of:屬「介係詞」，...