In class, we studied the small hard rock-like matter which is flung great distances when a volcano erupts.  What is the name of this substance?

Q. In class, we studied the small hard rock-like matter which is flung great distances when a volcano erupts.  What is the name of this substance?

A.            Lava

B.            Magma

C.            Tephra

D.            Pahoehoe

Answer: Tephra