The exercise described in this lesson (see text) should bring students to recognize and appreciate that the raw material(s) for making any item comes originally from biological and/or natural Earth material(s). As they pursue this, make sure that they recognize the materials for the item itself are but small portion. Have them consider as well the resources for the tools, and/or machines used, and energy and water requirements.
Lastly, but most importantly, bring in the human resources. Nothing at all would get made or done without people providing the resources of creativity and dedicated work in the multitude of jobs connected with making each of the resources available.
Finally, what are the resources necessary to maintain human life as we know it? In short, the resources required to make any item may draw into the picture all other resources, but be sure that students are able to cite the connections with thought and logical argument.