During the opening scene where the boys are assembling a door, Moe asks Curly to saw a piece of wood for him. Curly lays the wood on top of a wooden table, which Moe happens to be standing on.
In the opening sequence when the boys were constructing a door, Moe requested that Curly cut a piece of wood. Curly positioned the wood atop a wooden table, and Moe was standing on it.