What do stream terraces represent? Put another way, what were stream terraces before they became a terrace?

Which biochemical cycle is relied upon for plant photosynthesis

Acharreadas is a popular mexican thing where people display varying skills of horsemanship much like what events in the united states?

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