Dry farming became increasingly difficult in mesopotamia due to the problem of

Floods! Floods don't really happen to much, but there was a big one which caused the land to become super moist. Which made it difficult to do Dry Farming. I hope this helped! :)

Magma is outside the volcano  and lava is inside the volcano. 

It is useful for historians to write narratives so that history can be passed on from their point of view.  think about a story being told in third person, then think about it again being told in first person, by someone who actually experienced the event.