Answer:
Abu Bakr was an adviser and companion of the Prophet Muhammad. Abu Abu Bakr controlled the administration and later selected as caliph (ruler of the Islam community) after Muhammad's death. As a caliph, Abu Bakr launched many military campaigns to bring Arabia under Islam and was successful in expanding Islam further through conquering.
Answer: silk and metal (like bronze, steel or gold)
They gave us new ideas for war. Before wars were fught standing in a line and shooting at the other person, but after learning from the Native Americans they hid behind things and spread out they adapted to their surroundings. This is how Native Americans contributed to America.