Which statement is true? a. rural areas around urban areas often become urbanized. c. rural areas around urban areas rapidly lose population. b. rural areas around urban areas never become urbanized. d. rural areas around urban areas no longer exist.

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