Hey Buddy! I know this!
It was the Mongols who defeated the Pagan Kingdom.
Feel free to ask me more questions on my profile. :)
It was a social and economic system.
I would say that World War Two is a continuation of World War One because without Germany losing World War One Hitler would not have been able to take power in Germany. Another reason would be that without World War One Mussolini would not have had the right political climate to take power in Italy.
One problem is by trading by sea, ships are bring invaise sea creatures to other countries and can harm the wild life for other marine ecosystems and for tons of people.