Questions on the Chow ring of complete intersections

We state several questions, and prove some partial results, about the Chow ring $A^{\ast}(X)$ of complete intersections in projective space. For one thing, we prove that if $X$ is a general Calabi–Yau hypersurface, the intersection product $A^{2}(X) \cdot A^{i}(X)$ is one-dimensional, for any $i > 0$. We also show that quintic threefolds have a multiplicative Chow–Künneth (MCK) decomposition. We wonder whether all Calabi–Yau hypersurfaces might have an MCK decomposition, and prove this is the case conditional to a conjecture of Voisin.