What was the mandate system and what effect did it have?

This is an ap world history question. i am working on a worksheet which has a vent diagram with each circle labeled either us or byzantine economy. the middle is the similarities. can someone explain to me the similarities and especially the differences between the two?

Aschool principal trying to find out if parents will buy new playground equipment shows digital leadership by

Colton has trouble remembering information for his tests because he crams the night before. which would be the best study habit for colton to commit to? a. studying a little every day b. studying right before his tests c. studying in the evenings before bed d. studying only on saturdays