1. what were the crusades and what was their purpose?

their primary objectives were to stop the expansion of Muslim states, to reclaim for Christianity

Explanation:

The Crusades were organized by western European Christians after centuries of Muslim wars of expansion. Their primary objectives were to stop the expansion of Muslim states, to reclaim for Christianity the Holy Land in the Middle East, and to recapture territories that

The Crusades were organized by western European Christians after centuries of Muslim wars of expansion. Their primary objectives were to stop the expansion of Muslim states, to reclaim for Christianity the Holy Land in the Middle East, and to recapture territories that had formerly been Christian.Oct 25, 2019d formerly been Christian.

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering