Geologists distinguish three kinds of rocks, based on how they form: igneous rocks: solidified from a melt (i.e., formed when magma cools and freezes underground, or when lava [magma that has spilled out of a volcano] cools and freezes at the surface).
(magma; has spilled; out of a volcano; cools and freezes; L:at the surface) (three kinds of rocks; based; on how they form: igneous rocks: solidified from a melt (i.e., formed when magma cools and freezes underground, or when lava) (they; form; when magma cools and freezes underground, or when lava) (a melt; formed; )
magma three kinds of rocks they a melt
has spilled based form formed
out of a volcano cools and freezes L:at the surface
on how they form: igneous rocks: solidified from a melt (i.e., formed when magma cools and freezes underground, or when lava
when magma cools and freezes underground, or when lava