1. Puzzling conundrum: 令人困惑的谜题
2. Unsolvable conundrum: 无法解决的难题
3. Moral conundrum: 道德困境
4. Political conundrum: 政治难题
5. Intellectual conundrum: 知识上的难题
6. Ethical conundrum: 道德难题
7. Cultural conundrum: 文化难题
8. Economic conundrum: 经济难题
9. Existential conundrum: 存在难题
10. Logical conundrum: 逻辑难题
11. Personal conundrum: 个人难题
12. Social conundrum: 社会难题
13. Scientific conundrum: 科学难题
14. Technological conundrum: 技术难题
15. Conundrum of choice: 选择的难题