Vacuoles are essentially sacs surrounded by a membrane. They are used by cells as temporary storage sites. They often store food, enzymes, and other materials needed by the cell, and some vacuoles store waste products.
I believe flowing water would create erosion because tectonic plate movement and earthquakes are almost the same thing, and liquid rock is basically lava, and that only heats rock, rather than breaking it into smaller pieces, which is what flowing water does.
