  This paper studies the propagation connectivity of a random hypergraph
$\mathbb{G}$ containing both 2-edges and 3-hyperedges. We find an exact
threshold of the propagation connectivity of $\mathbb{G}$: If
$I_{\epsilon,r}<-1$, then $\mathbb{G}$ is not propagation connected with high
probability; while if $I_{\epsilon,r}>-1$, then $\mathbb{G}$ is propagation
connected with high probability, where $I_{\epsilon,r}$ is a constant dependent
on the parameters of 2 and 3-edge probabilities.
