If that Martian looked at battlefields, they would find that people had only muskets at the time of the Civil War and that they had repeating rifles at the time of the Spanish-American War, and then they had machine guns by the time of World War I.
Se o marciano olhasse  para os campos de batalha, descobriria que as pessoas  só tinham mosquetes na época da Guerra Civil, que tinham espingardas de repetição na época da guerra hispano-americana, e que, depois, tinham metralhadoras na época da I Guerra Mundial.