Most
volcanoes
____________________
form
at
the
edges
of
tectonic
plates
.
These
huge
plates
____________________
constantly
shift
.
Sometimes
,
the
plates
____________________
pull
apart
or
could
slide
into
each
other
.
When
this
happens
,
magma
____________________
rise
to
fill
in
the
space
.
Strong
pressure
and
intense
heat
____________________
force
the
magma
upward
.
