1) What are primary and secondary sources? - The examples of primary sources are written, oral, pictorial evidence and artefacts. - The examples of secondary sources are like a legend and a myth.
2) How do historians make sure that their sources are reliable? - They make sure it by testing the three C's which are credibility, consistency and corroboration.
3) Why and when is it necessary for historians to revise their interpretations of past events? - It is necessary for historians to do so when archaeologists discovered new artefacts because such evidence can provide new ways of looking at the past.