for (Iterator i = response_labels.iterator(); i.hasNext();) {
ChoiceResponse choice = new ChoiceResponse();
Element response_label = (Element) i.next();
choice.setIdent(response_label.attributeValue("ident"));
List materials = response_label.selectNodes(".//material");
Material content = new Material();
for (Iterator iter = materials.iterator(); iter.hasNext();) {
Element el_material = (Element) iter.next();
Material mat = (Material) parserManager.parse(el_material);
content.getElements().addAll(mat.getElements());