Author Question: Mass extinctions at the end of the Ordovician occurred because of: a. dramatic changes in oceans ... (Read 78 times)

rosent76

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Mass extinctions at the end of the Ordovician occurred because of:
  a. dramatic changes in oceans related to glaciation.
  b. dramatic chemical changes in seawater related to meteorite impact.
  c. increased solar radiation.
  d. decreased solar radiation.
  e. dramatic changes in oceans related to glaciation AND increased solar radiation.



Question 2

The Precambrian-Cambrian boundary represents the first appearance of:
  a. vertebrates.
  b. amphibians.
  c. reptiles.
  d. animals with skeletons.
  e. animals with soft bodies.




dellikani2015

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Answer to Question 1

Av

Answer to Question 2

D



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