Chapter 4, Problem 4.4CP

Does the enthalpy of formation of $H_{2}O\left(l\right)$ change if the absolute enthalpies of $H_2\left(g\right)$ and $O_2\left(g\right)$ are set equal to $\text{1}00.{\text{ kJ mol}}^{-\text{1}}$ rather than to zero? Answer the same question for $C{O}_2\left(g\right)$. Will $\Delta H_R^{°}$ for the reaction $H_{2}O\left(l\right)+C{O}_2\left(g\right)\to H_{2}C{O}_3\left(l\right)$ change as a result of this change in the enthalpy of formation of the elements?