Which gas is the most abundant of the trace gases? nitrogen oxygen argon carbon dioxide

The earth's internal process which drives seafloor spreading is

Based on current rates the earths human population is expected to grow how much by 2050

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