A substrate is coated with a hydrophobic coating that includes highly tetrahedral amorphous carbon that is a form of diamond-like carbon. The photopolymerizable composition and the photosensitive thermal recording material of the invention are highly sensitive to UV rays and visible to IR rays falling within a wavelength range that includes wavelengths not longer than 450 nm, and are effective for decoloring a dye component that absorbs the rays falling within the wavelength range. The acrylic elastomer layer 11 and the fluorine-based elastomer layer 12 are laminated, to give a laminate body 1. An impurity concentration of the first sub-epitaxial layer is less than that of the second sub-epitaxial layer. The students do basic music ear training exercises using percussion instruments to focus on the rhythm of sound and to develop listening and concentration skills.