What were the main causes of the fall of the Roman empire? a. Decline in learning and education.
b. Loss of a common language.
c. Trade decline and cities depopulated
d. All of the above.

D

Explanation:

Don't really got an explanation but I know it's right.

D. All of the above

Explanation:

The Romans conquered so much land, they lost a common language, as people in the Roman Empire were all speaking the language of their home lands. They had a decline in learning and education during this period also. There was less trade and cities were depopulated because of Rome's enormous territory. Less trade was needed because Rome already had everything in it that it needed.  

answer; /// (c) i believe that the correct answer is; ///full faith and credit.

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering