Small pieces of rock that enter earth's atmosphere at speeds of 15 to 70 km/s and burn up are called
stars

meteors

meteorites

asteroids

a comet develops a coma because of
gravity

earth's atmosphere

the oort cloud

heat from the sun

the answer is:

c. islam and christianity

explanation:

islam and christianity are widely practiced in africa. islam is practiced due to its spread from the middle east into africa, and christianity is practiced due to the colonization of africa by the british empire.

landlessness of ordinary people

^^something like that^^^