How have we learned about soldiers' firsthand experiences during the Civil War?
A. Through the president's speeches
B. Through personal memoirs
C. Through newspaper accounts
D. Through interviews

Which of the layers of the earth has the following three characteristics? i. it is a solid outer layer. ii. it is between 3 and 30 miles thick. iii. it is separated into plates. a. the outer core b. the inner core c. the mantle d. the crust