  Let $X$ be a Noetherian separated scheme of finite Krull dimension. We show
that the layers of the slice filtration in the motivic stable homotopy category
$\stablehomotopy$ are strict modules over Voevodsky's algebraic cobordism
spectrum. We also show that the zero slice of any commutative ring spectrum in
$\stablehomotopy$ is an oriented ring spectrum in the sense of Morel, and that
its associated formal group law is additive. As a consequence, we get that with
rational coefficients the slices are in fact motives in the sense of
Cisinski-D{\'e}glise \cite{mixedmotives}, and have transfers if the base scheme
is excellent. This proves a conjecture of Voevodsky \cite[conjecture
11]{MR1977582}.
