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：6. Q: What is Secret's most popular song? 答： A: Secret's most popular song is "Poison," which was released in 2014 and became a huge hit in South Korea.
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.