According to the passage, iron …………

Iron has been known since prehistoric times. Although how humans first learned to extract the element from its ores is still debated, it is fairly certain that earliest, highly prized samples of iron were obtained from meteors. Several references to “the metal of heaven” — most probably iron —have been found in ancient writings. By about 1200 BC, iron was being obtained from its ores; this achievement marked the beginning of the Iron Age. Even with the development of other materials, iron and its alloys remain important in the economies of modern countries.