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One of the successes of the standard big bang model is its ability to reproduce the observed abundances of the light elements, particularly $^4 He$ and $^7Li$. The abundance of $D$, however, is much harder to test observationally since $D$ is destroyed in stars. We can search for galactic chemical evolution models which reproduce the present-day and pre-solar values of $D$ starting with a primordial value which is consistent with a baryon-to-photon ratio of $3 \times 10^{-10}$. We consider galactic chemical evolution models to test for the destruction of D which constrain the age of the galaxy at the time of the formation of the solar system and consequently its present day age from nucleochronometers. We consider models with exponential star star formation rates and star formation rates proportional to powers of the gas mass. We include infall in our models of rates proportional to the gas mass and exponentially decreasing rates. We consider initial disk enrichment in the range of 0\char37 to 30\char37. We present those models which give the observed pre-solar value and present-day value which lead to a present-day gas fraction of $\sigma \sim .1\quad - \quad .2$.
