Implications of the large ${B}_{d}^{0}$-B\ifmmode\bar\else\textasciimacron\fi{} $_{d}^{0}$ mixing measured by the ARGUS Collaboration are examined. Possible large top-quark mass is estimated. In addition, large CP-nonconservation effects in the two-body nonleptonic decays of ${B}_{d}^{0}$-B\ifmmode\bar\else\textasciimacron\fi{} $_{d}^{0}$ and ${B}_{s}^{0}$-B\ifmmode\bar\else\textasciimacron\fi{} $_{s}^{0}$ are recalculated. The results show that we still need \ensuremath{\sim}${10}^{6}$ ${B}_{d}$,${\mathit{s}}^{0}$-B\ifmmode\bar\else\textasciimacron\fi{} $_{d}$,${\mathit{s}}^{0}$ pairs for testing these CP-nonconservation effects in the ${B}_{d}$,${\mathit{s}}^{0}$-B\ifmmode\bar\else\textasciimacron\fi{} $_{d}$,${\mathit{s}}^{0}$ system.