A、Asinglerowsubquerycanretrieveonlyonecolumnandonerow.
B、Asinglerowsubquerycanretrieveonlyonerowbutmanycolumns.
C、Amultiplerowsubquerycanretrievemultiplerowsandmultiplecolumns.
D、Amultiplerowsubquerycanbecomparedusingthe"；>；"；operator.
E、AsinglerowsubquerycanusetheINoperator.
F、Amultiplerowsubquerycanusethe"；="；operator.