I know the answer to this, but let's see if you guys can solve this

Explanation:

b. only Jack is cporrect

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)

there is none because earth is stationary and flat.