My group is doing the Nervous System. In our last lesson we began to build the base of our working model and began constructing the arms. The arms were made of big plastic bottles and the base was made of cardboard. We realised that one of the materials we were planning to use might be a problem. This material was the helium balloons because after a while the helium runs out and won’t float anymore.  I am in charge of bringing clay (to make the brain), food colouring (for a more easily seen version of water), and 10 water bottles (both to hold the fluid, and to make the arms).