the theory that the sun is the center of the solar system is known as the
a. heliocentric theory*
b. geocentric theory
c. oscillating theory
d. big bang theory

Litmus paper is made from water-soluble dyes which are extracted from lichens. this paper is used as an acid-base indicator. which of these common household substances would turn blue litmus paper red? a) bleach b) lye c) soap d) vinegar

The continuous release of nuclear energy caused when one fission reaction triggered more nuclear reactions is a

Skills of homo sapiens were found an excavation. the skulls were preserved because the bodies were frozen. so, these fossils are (blank) fossils. the image shows the evolution of skulls beginning 2 to 3 million years ago. based on the image, modern human skulls(blank) ape skulls.