트롤리 딜레마
https://www.youtube.com/watch?v=yg16u_bzjPE
수수께끼
https://www.youtube.com/watch?v=1rDVz_Fb6HQ&list=PLJicmE8fK0EiFRt1Hm5a_7SJFaikIFW30&index=4
https://www.youtube.com/watch?v=ZKh6z0X6KRw&list=PLJicmE8fK0EiFRt1Hm5a_7SJFaikIFW30&index=10
https://www.youtube.com/watch?v=tE2dZLDJSjA&list=PLJicmE8fK0EiFRt1Hm5a_7SJFaikIFW30&index=14