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：冰桶挑戰的起源是什麼？ 答：冰桶挑戰最早起源於2014年，由前棒球運動員皮特·弗蘭斯（Pete Frates）等人發起，目的是為了提高對ALS的認識和籌款。