The correct answers to this open question are the following.
My speculation about the purposes of the South American Nasca drawings and the Serpent Mounds of North America are the following.
The Nazca drawings are located in a desertic area in Peru. They are a series of lines and animal figures that only can be devised by air. These long lines look like landing tracks such as the ones that are built in airports. So one of the theories that Nazca was a landing place for ET's starships. The animal figures meaning are still a mystery.
On the other hand, the Great Serpent Mound is located in southwest Ohio, United States. It is a long mound with the form of a large serpent. People give it mystical meanings due to the fact that the head of the mount or"serpent" aligns with the sunset in the summer solstice. Archeologists debate about the meaning of the mount: some say it was a kind of celestial compass. Others think there were totems over the mound.
Answer:
Around 1.8 million years ago, Homo erectus migrated out of Africa via the Levantine corridor and Horn of Africa to Eurasia. This migration has been proposed as being related to the operation of the Saharan pump, around 1.9 million years ago.
Explanation:
Intermediate-Range Nuclear Treaty
It has to do with the governments system, whether it is a democratic republic, demo-socialist, communist, etc. This plays huge roles in their economic systems, causing it to vary country to country.
The answer to the question is number 2
Fidel Castro’s revolution in Cuba
Hope that helped!❤️