3-D printing can change the world. It could help end a lot of the world’s problems, such as world hunger and perhaps poverty too, but only if used in the right way. Most people 3-D print small objects, like name tags. But, what if every household had a food 3-D printer? What if 3-D printed houses are made and sold? It could solve a lot of problems. Overall, 3-D printing is very useful.