  The existence of the five-quark Fock states for the intrinsic charm quark in
the nucleons was suggested some time ago, but conclusive evidence is still
lacking. We generalize the previous theoretical approach to the light-quark
sector and study possible experimental signatures for such five-quark states.
In particular, we compare the $\bar d - \bar u$ and $\bar u + \bar d - s -\bar
s$ data with the calculations based on the five-quark Fock states. The
qualitative agreement between the data and the calculations is interpreted as
evidence for the existence of the intrinsic light-quark sea in the nucleons.
The probabilities for the $|uudu\bar{u}>$ and $|uudd\bar{d}>$ Fock states are
also extracted.
