Answer:
New innovative ways to build the ships and keep people safe
Explanation:
^^
1) They mostly spread Islam through conquering new countries. What they did also was unite all people under a single rule and ended religious uprisings.
2) There was tensions because one faction believed that Muhammad should be succeeded by someone chosen by people, while the other faction believed that his successor should be someone from his bloodline.
1933 was the year that brought the close of 500 different banks in the United States of America.
