The main way astronomers determine the physical and chemical properties of an object in the distant universe is through

a) photography

b) spectroscopy

c) astrometry

direct measurement

d direct measurement

What is the primary justification of the hypothesis that the early earth environment was void of oxygen? ( 2 points) data showing the concentrations of gases extracted from rocks fossil evidence regarding the origin of eukaryotes generally accepted atmospheric conditions molecular evidence based on evolutionary traits.

After considering options, a student using the problem-solving process should next

In which horizon of soil profile is prevent material usually found