Completar Frases Exercise 10. Complete the text (Pollution)Versión en línea Complete this text. por Teacher Diana Liz Villalbante 1 Pollution materials volcanic damage factories trash environment runoff human harmful pollutants is the introduction of materials into the . These harmful are called . Pollutants can be natural , such as ash . They can also be created by activity , such as or produced by . Pollutants the quality of air , water , and land .