Answer:
Retrograde Motion
Explanation:
Geocentric model of planets was proposed by Ptolemy. It stated that all sun, planets and stars revolve round the earth in circular orbits.
NOTE: Ptolemy: an ancient astronomer, geographer, and mathematician who considered the Earth the center of the universe (the "Ptolemaic system").
It is used in such good quality papers that need high opacity, higher brightness and whiteness such as offset papers and bible papers. ... But only rutile and anatase are used in paper mill industries. Both are tetragonal crystalline system. Rutile has higher refractive index than anatase.
Answer: i dont understand
Explanation: