Answer
The quark combination $uu\bar{s}$ can not produce $\Sigma^+$
Work Step by Step
The $\Sigma^+$ has strangeness $-1$
The up quark $u$ has strangeness $0$
The strange antiquark $\bar{s}$ has strangeness $+1$
The net strangeness of $uu\bar{s}$ is $+1$
Therefore, the quark combination $uu\bar{s}$ can not produce $\Sigma^+$
