The Romans divided their law into jus scriptum (written law) and jus non scriptum (unwritten law). By “unwritten law” they meant custom; by “written law” they meant not only the laws derived from legislation but, literally, laws based on any written source.
Marbury v. Madison is important because it established the power of judicial review for the U.S. Supreme Court and lower federal courts with respect to the Constitution and eventually for parallel state courts with respect to state constitutions.
The time frame is slightly important. Though for the most part that is false. The Chinese leaders did not see the need to interact with outside societies as they had little reason to trade. b. False