There were many problems, like the bottom of the water bottles, rust, making the lever run smoothly, synchronizing the bottles so they aligned, putting the sponges in the large intestine, and other stuff. However, we didn’t use trial and error until we actually needed to. The bottom of the water bottles were stumps we couldn’t cut across, so we cut around it. Some problems were human error (mostly me). I thought that the gap between the edges was too narrow, so I cut them to make it less narrow. However, I didn’t know that the edges were supposed to be narrow (communication problem on my part), so I ended up with rough edges, so I put tape around it, reinforced the bottles with cardboard, glued it, then cut it again. This made the lever run smoothly. I synchronized the bottles by putting cardboard on it, until it fit, then reinforced it with glue and tape. We just shoved the sponge in the bottles, then glued it. However, these were pretty minor problems (other than the bottoms of the bottles). The biggest challenge for me was teamwork. I usually branched off from my group and would do stuff by myself, sometimes giving advice to other people, and even doing things myself, but still, 50% of the time, I was working alone. If I didn’t simply branch off and decided to work with my other group members, I might have done things quicker. However, we had enough resources and managed to pull it off.