Bipartite Graphs and Matchings · Challenge problem

Of the following five pairs of degree sequences for a bipartite graph (written as (row sums, column sums)), how many can actually be realized by SOME bipartite graph? (1) $(3,3,3),(3,3,3)$. (2) $(3,3,3),(2,2,2)$. (3) $(2,2,2,2),(3,3,1,1)$. (4) $(4,1,1,1,1),(4,1,1,1,1)$. (5) $(3,2,2,1),(3,2,2,1)$.