Using The graph to answer 12 and 13. Number 14, 16, and 17 answer don't have to use graph. Please Help ASAP. 12- In The graph Below what events do these arrows mark? What happens during these events?

13- What event appears to have had the greatest impact? Explain your answer in terms of the Graph

14- What are two possible reasons why large poulations of organisms die?

16- Why did new and existing aquatic organisms flourish during the Mesozoic era? Use The terms glaciers, Pangaea, and sea level in your explanation.

17- Approximately how long did Precambrian time last?

A- 0.5 Billion years

B- 3.5 Billion years

C- 4.0 Billion years

D- 4.25 Billion years