China and japan turned away from contact with foreigners beginning in about 1450. which was not a reason for doing this?
a. determination to keep outsiders from changing traditional beliefs and practices
b. realization that their civilizations were backward and poor
c. fear that europeans would try to take power and control them
d. desire to remain economically and culturally self-sufficient

What is the main difference between primary and secondary sources? a. primary sources are historical documents, and secondary sources are modern-day documents. b. primary sources are derived from museums and archives, and secondary sources are created by history students and academics. c. primary sources are found in ancient places with a rich history, and secondary sources are found in historical journals and blogs. d. primary sources are created during a particular historical era, and secondary sources are created by studying primary sources.