What is the most complex machine ever invented? The Human Body. Everyone knows what the human body looks like on the outside, but what does it look like on the inside? Explore this and more in our Project Pack, The Human Body. Included in this 104-page Project Pack you and your students will find a detailed 13-page Research Guide that covers the six major systems of the body; Cardiovascular, Digestive, Nervous, Muscular, Respiratory, and Skeletal. As always, the guide also includes fun links for more research opportunities and a vocabulary list. Also included in this Project Pack are 21 hands-on activities that correspond to the information covered in the guide. Explore how the systems of the human body work together to make this complex machine function in our Project Pack, The Human Body.