The Earth formed... a. ) about 4.5 billion years ago b. ) about 4.5 quadrillion years ago c. ) about 4.5 million years a

[answerhappygod]

The Earth formed...
a. ) about 4.5 billion years ago
b. ) about 4.5 quadrillion years ago
c. ) about 4.5 million years ago
d. ) around 6,000 BC
Evidence for the existence of dark matter:
a. ) is presently very weak
b. ) comes mainly from Cepheid stars
c. ) comes from rotation curves of galaxies
d. ) can be found in the Moon's orbit around the Earth
According to Hubble's Law, if a galaxy is far, far away it
will:
a. ) emit light that is blue-shifted
b. ) be very, very bright
c. ) have a large parallax
d. ) move away from us very, very fast