How were the civilizations of the huang river valley and the nile river valley similar?

These two river valleys were similar, because they both had a government form in hierarchy. They both had a ruler, and they were in the monarchy system. Some of the systems were considered to be well off systems because they were able to rule without disruptions and others had systems which were not in equality with men and women.

porter is writing economic history because he is focusing on the cost of developing vaccines.

cultural/diplomatic relations. most medieval japanese   culture has chinese origins. writing, architecture etc.