  We prove that every $C^1$ generic three-dimensional flow has either
infinitely many sinks, or, infinitely many hyperbolic or singular-hyperbolic
attractors whose basins form a full Lebesgue measure set. We also prove in the
orientable case that the set of accumulation points of the sinks of a $C^1$
generic three-dimensional flow has no dominated splitting with respect to the
linear Poincar\'e flow. As a corollary we obtain that every three-dimensional
flow can be $C^1$ approximated by flows with homoclinic tangencies or by
singular-Axiom A flows.
