Let G_n be the bipartite graph with vertices \{x_1,\ldots,x_n,y_1,\ldots,y_n \} and edges \{x_iy_j:i<j\} and suppose \epsilon > 0. Find a constant M \geq 2 and (for sufficiently large n) an explicit \epsilon-regular partition of G_n into M pieces. Also, how can you show that there is not a constant M such that every G_n has a partition into M (almost) equal vertex classes in which every pair is \epsilon-regular?