One hypothesis about the origin of the building blocks for life is that they werea. made inside meteors.
b. formed when lightning struck water.
c. started by the rna in the ocean.
d. brought to earth by meteorites.

Which greenhouse gas is emitted when burn fossil fuels for energy? a.nitrogen b.oxygen c.carbon dioxide d.helium

What happens when a scientific theory is shown to be an accurate description of a phenomenon?

When it is summer at the south pole, a. the northern hemisphere is tilted toward the sun. b. the southern hemisphere is tilted away from the sun. c. the northern hemisphere is tilted away from the sun. d. both the southern and northern hemispheres are tilted toward the sun.