sentences:  Materials include cloth, corrugated iron, cardboard, wood, plastic, and sometimes also bricks or cement.According to Sheela Patel of the Society for the Promotion of Area Resource Centers (SPARC), pavement dwellers are primarily first generation migrants who moved to Mumbai as early as the 1940s, and who have lived on the pavement of public roadways ever since.They are completely invisible as far as local, state, and national policies are concerned.