What is important about the minerals calcium and iron ?

Macro means "large" in Greek (and your body needs larger amounts of macrominerals than trace minerals). The macromineral group is made up of calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur. ... Trace minerals includes iron, manganese, copper, iodine, zinc, cobalt, fluoride, and selenium.

answer; philip zimbardo;

yes because there are aliens