Historians use the term "middle ages" to refer to the period
from the end of the western roman empire to the end of the eastern (byzantine) empire
from the end of the ancient world until the european renaissance
from 476 until 1453
all of the answers are correct.

. political or economical policy that isolates a country from participating in international relationships. it has been suggested that the united states participates in isolationism because of its lack of involvement in particular wars or alliances.

1. it was caused by feudalism

2. charlemagne used christianity as a major cornerstone for his rule. cloisters were built all over the empire to act as centers for the (re)population of the vast european wilderness.

3. the europeans feared the next raid every time chetak

i'm not so sure about #6. but i hope i you with the first 3.