<prompt> tafadhali geuza maudhui haya ya swahili kwenda kwa kiingereza.freiburg pia inajulikana kama jiji la eco, sio moja tu ya miji safi zaidi duniani lakini pia ni miji mikubwa zaidi duniani inayotumia nishati ya jua.  <response>: freiburg also renowned as an eco city is not only one of the cleanest cities in the world but also one of the cleanest cities in the world but also one of the greenest cities in the world. 