Caves form mostly from the reaction of weak carbonic acid (which forms due to carbon dioxide that is in the water) with exposed limestone. What numbers go in the blanks below, in order from left to right, to balance this chemical equation? ___H2CO3(aq) + ___CaCO3(s) --> ___Ca(HCO3)2(aq) + ___CO2(g) + ___H2O(l)