常見問題：
問：4. Q: What was Secret's debut song? 答： A: Secret's debut song was "I Want You Back," released in 2009.
問：9. Q: What is the reason behind Song Ji-eun's departure from Secret? 答： A: Song Ji-eun left Secret in 2014 to focus on her solo career and acting.
問：冰桶挑戰的目的為何？ 答：冰桶挑戰的主要目的是提高對肌萎縮性側索硬化症（ALS）的認識，並為相關的研究和治療籌集資金。