1. malaria 2. rivers had terrible waterfalls..too dangerous...until the steam engine was invented it was incredibly dangerous 3. deserts....they didn't know how to travel through the deserts and find an oasis which made it very difficult to travel through
Answer:
I think the letter was about the first atomic bomb.
Explanation:
''The Einstein–Szilárd letter was a letter written by Leó Szilárd and signed by Albert Einstein that was sent to the United States President Franklin D. Roosevelt on August 2, 1939. ... It prompted action by Roosevelt, which eventually resulted in the Manhattan Project developing the first atomic bombs.''
got the explanation from wikipedia, hope this helps.
It was maybe the lack of British loyalists in the country, the lack of troops in the country, and France and Spain's involvement in the revolution<span />
The main weapon that enabled the Europeans to conquer vast amounts of territories in distance lands was all the new sicknesses that were brought along with them. As stated in the book Guns, Germs and Steel written by <em>Jared Diamond</em> in 1997. The author explains that the Europeans had the technological advances of the era, such as gun powder, rifles, and cannons, but their most devastating weapon was the side effect of their presence, the presence of foreign bacteria to new populations.
