【Stu】評論
osteoporosis ：骨質疏鬆症解題：題目問是什麼導致骨質疏鬆，解題關鍵在第三段的第一句＂When the rate of bone renewal doesn’t equal the rate of breakdown, bone loss results. When the bone loss becomes advanced, it is called osteoporosis.＂當骨質更新頻率不等於分解率時，就會導致骨質疏鬆流失。當骨質流失的狀況惡化，稱為骨質疏鬆症。答案選（Ｄ）Insufficient bone renewal 骨質更新不足