He tropical climate in the guianas is an example of
a.
a similarity between this area and the rest of the region.
c.
a threat to the environment in the region.
b.
an important aspect of the guianas economy.
d.
a difference between this area and the rest of the region.

Why is the huronian supergroup rock formation particularly interesting to scientists? because it looks like a cross-section of a giant, stone encyclopedia because it formed during the period when oxygen began to accumulate in the atmosphere because it contains unusually large amounts of oxygen and sulfur because it dramatically altered the planet's development when it first formed