If magma is thin and runny, gases can escape easily from it. When this type of magma erupts, it flows out of the volcano. ... If magma is thick and sticky, gases cannot escape easily. Pressure builds up until the gases escape violently and explode.
<span>The three major rivers which flow through France are the Loire river (the longest at 625 miles long), the Rhone river and the Seine river.</span>
