The first president of the U.S. was George Washington. He served as president before any other president. 
        
             
        
        
        
The invention of agriculture helped to meet the nutritional needs of people easier which helped them live longer. This also caused the people who moved around to settle down in one area to farm.
        
             
        
        
        
Answer:
They most likely would have sent messages like if they won or lost a battle. The modern Athens Marathon commemorates the run of a messenger from a battlefield at the site of the town of Marathon, Greece, to Athens in 490 B.C. Legend has it that a messenger delivered the momentous message “Niki!” (“victory”), then collapsed and died. Maybe messages of where they should meet for battle, so if the figure out the enemy is attacking 50 miles west of where they were they could message their allies to meet there instead. 
Explanation:
 
        
             
        
        
        
The event of the dropping of the atomic bombs led to the end of World War II in Asia.
Answer: Option B
<u>Explanation:</u>
The Japanese Emperor kept carrying out war acts despite repeated warnings from the United States and its allies to surrender. The United States under the President-ship of Franklin D. Roosevelt finally decided to drop atomic bombs on the Japanese cities of Hiroshima and Nagasaki.
These bombs were dropped on two different days, viz. 6 and 9 August 1945, following which, Japan surrendered and the war was ended.