Columnar joints caused by the contraction of lava as it cools ...

[mpobi80]

Columnar joints caused by the contraction of lava as it cools form typically in a(n)
  ___________________ _ shape. Fill in the blank(s) with the appropriate word(s).

Question 2

One common but dangerous gas emitted from volcanoes, which was responsible for many deaths in
  Cameroon, is ___________________ _. Fill in the blank(s) with the appropriate word(s).

[akemokai]

Answer to Question 1

polygonal
polygonal often six-sided
six-sided

Answer to Question 2

carbon dioxide

[mpobi80]

Correct answers!

[akemokai]

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