(c) where the effects described in paragraphs (a) and (b) have been shown to be caused solely by physical abrasiveness due to the presence of insoluble particulates;" nor
」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」」＜第２章　物質の構成粒子＞（教p19-）