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：10. Q: Are Secret still active as a group? 答： A: Yes, Secret is still active as a group, with the remaining members continuing to release music and participate in various activities.