Which of the following statements best describes the spread of islam under the first four caliphs?

The statement that best describes the spread of Islam under the first four caliphs is Arabs united under Islam and defeated nearby empires.

Explanation:

As for the others if you need help

1. B) Arabs united under Islam and defeated nearby empires.

2. B) Weakened Persian and Byzantine rule and C) Darling, effective fighting methods.

3. D) The Umayyads expanded into Spain.

4. B) Persian traditions strongly affected the caliphate. and D) Non-Arab Muslims were allowed to hold powerful positions.

5. D) It introduced them to a wide body of medical knowledge and the idea of training physicians and creating hospitals.

6. A) Chivalry and the romance of nomadic life.

^These should all be confirmed correct as of 12-14-21 for connections. Hope this helps! :D

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering

genetics is the study of how dna works, the methodologies defining the new recent technologies allow scientist to have a panoramic view of the entire dna landscape, especially how genomes interact with their environment, including off course, factors outside their organisms.

thus is very possible the existence of both scenarios, where populations of isolated individuals have different genetic traits, and share traits related to genetic mutation, due rats can easily travel overseas using human transport channels. so scientists could get a vast number of data, including human interaction, evolution of rodents, health development, spread of infections, development of new organisms, how genomes evolve in different environments and so on.