Glassy igneous rocks (i.e. obsidian) are cooled very rapidly.
The statement water is easily polluted..... is true. Water is pretty much the world's best solvent. So even toxic substances are easily dissolved in it and when that happens they pollute the water.
The ovaries produce the egg cells, called the ova or oocytes. The oocytes are then transported to the fallopian tube where fertilization by a sperm may occur. The fertilized egg then moves to the uterus, where the uterine lining has thickened in response to the normal hormones of the reproductive cycle.