I am so confued on Changing Economic World Resources topic

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

What landform caused by water erosion and deposition is shown in the image?

Major river of southeast asia flowing through laos thailand vietnam and cambodia