國際教育教材備用
[Flags]
https://www.youtube.com/watch?v=e8OEuj6-pVg
三色條紋國旗簡介
http://tech.huanqiu.com/discovery/2016-08/9348625.html
三色條紋旗由來(簡體版)
https://www.youtube.com/watch?v=BLNzJWscXEk
*country size comparison
https://www.youtube.com/watch?v=uOn7TDzfUPA
[Anthem]
11首過期不再用的"國歌"
https://www.youtube.com/watch?v=UTEKpruiYsU
10 anthems (selective, no comment, only for introduction)