関連ワード:  concave mirror definition class 7    concave mirror definition class 7 science    concave mirror definition class 7 ncert    spherical mirror definition class 7    convex mirror definition class 7    convex mirror definition class 7th    spherical mirror definition class 7 science    spherical mirror definition class 7 ncert    convex mirror definition class 7 science    convex mirror define class 7