The death of archduke Francis Ferdinand of Hungary was the initial cause of ww1. However there was a build up to ww1. Countries had new powerful weapons and wanted to capitalise on this. The navy’s of many countries were being expanded. Political disagreements between countries led to increased tensions.
Answer:
communication
Explanation:
due to writing we are able to communicate fluently with one another
I believe it was the Stock Market Crash of 1929
