How many more metric tons of coal were produced in 1938 than in 1928

Iron making developed in china almost a thousand years later than in the middle east. true false

Which of the following was a factor in the development of the english common law ?

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 a. primary sources are historical documents, and secondary sources are modern-day documents.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