What means: a material that has spaces that allow water to seep through

2. x2 + 8x + 12 = 0 to prove: x = -6 or x = -2

Answerdistinguish between the mercalli scale and the richter scale;

Answer the collision of tectonic plates;

It is useful for historians to write narratives so that history can be passed on from their point of view.  think about a story being told in third person, then think about it again being told in first person, by someone who actually experienced the event.