Exploration can be traced to the Phoenicians, Muslims, and Chinese
but
was the front-runner in
European exploration.
A. Russia
B. Polynesia
C. Vikings
D. Portugal

D. Portugal

Explanation:

i discarded the supernatant and kept the pellet in this part of the experiment because you have to return all unused chemicals into their original containers at the end of each labratory.

explanation:

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering