look up the current us gdp - find a graph. based on gdp alone, do you think we are in a recession or an expansion? why? (make sure you're looking at gdp, not gdp per capita! )

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