Read the following passage from a book that david livingstone wrote about his travels in central africa. "the country is becoming very beautiful, and furrowed [lined] by deep valleys; the underlying rocks, being igneous, have yielded [given] fertile soil. there is great abundance of large game [animals to hunt]. . we crossed the mbai [river] and found in its bed rocks of pink marble. some little hills near it are capped by marble of beautiful whiteness." which best summarizes livingstone’s description of africa?

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 a. primary sources are historical documents, and secondary sources are modern-day documents.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.