Dark matter may explain _____.
A.unexpected orbital velocities of stars in galaxies
B.the source of energy that fuels stars
C.the expansion of the universe
D.the origin of life
E.what came before the big bang
A.unexpected orbital velocities of stars in galaxies
B.the source of energy that fuels stars
C.the expansion of the universe
D.the origin of life
E.what came before the big bang