  The availability of data on $B_s$ decays to strange quasi-two-body final
states, either with or without charmonium opens new possibilities for
understanding different contributions of weak diagrams and in particular the
relative contributions of tree and penguin diagrams. Corresponding $B_d$ and
$B_s$ decays to charge conjugate final states are equal in the SU(3) symmetry
limit and the dominant SU(3) breaking mechanism is given by ratios of CKM
matrix elements. Final State Interactions effects should be small, because
strong interactions conserve $C$ and should tend to cancel in ratios between
charge conjugate states. Particularly interesting implications of decays into
final states containing $\eta$ and $\eta'$ are discussed.
