Cities like Timbuktu and djenne were important because

They were important trade cities, and also housed some of the best education.

Explanation:

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

the two things that develop a strong social foundation are: a. separation of church and states e. education received attention separation of church and states separate the illogical  argument that came from religious beliefs to a fact based belief. while education will make us remember the past to avoid the repeat of our mistakes.