Earth is the third planet from the sun and is the only planet that has on it, as far as we know

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)

wher is the rest of the question

catya your not at all which answer i've seen you do this on another question!