Fotos: v.l.n.r.(Desktop+Tablet)/v.o.n.u.(Handy): © Berwis/pixelio.de, web4schools, Stephanie Hofschlaeger/pixelio.de, Rainer Sturm/pixelio.de, web4schools, Karin Jung/pixelio.de, Peter Draschan/pixelio.de, Flickr.com, Dieter Schütz/pixelio.de, 3 x web4schols, Flickr.com, twinlili/pixelio.de, web4schools, Dieter Schütz/pixelio.de