until thE Big golD DisCovEriEs in thE lAtE ninEtEEnth CEntury ______.
A．most nAtions ADoptED thE golD stAnDArD
B．thE trADing nAtions wErE unABlE to gEt Enough golD
C．golD Coins wErE usED By most nAtions
D．golD CEAsED to BE An importAnt mEtAl