46. explain why people on earth can only see one side of the moon and never
the other.

Where do homologous chromosomes exchange genetic material through crossing over?               a.  chlorophyll    b.  centrosomes    c.  centromeres    d.  chiasma

Melissa lives in a town called greendale. she discovers that when she lights a match and holds it near her kitchen faucet, the little flame grows into a larger fire. melissa is surprised because she thought the water would extinguish the flame rather than ignite it further. her mother tells her that the water might be contaminated with dissolved methane, a primary component in natural gas. melissa investigates the matter and finds that cases of methane contamination started shortly after a company began fracking for natural gas in the area. based on this information, which three statements are plausible consequences of fracking in greendale?

What was the land like over 500 million years ago? what was under the sea?