overpopulation is the result of a combination of many factors. first the world's population keeps rising.(11)......... health care is better, more and more people live longer . There are fewer deaths at birth.there are more and more people on (12).........Second ,immigration into urban areas has caused overpopulation in big(13)............Industry has developed greatly since the industrial Revolution, drawing a lot of farmers to cities to(14).................... in factories. Cities are (15)..............crowded while there are not enough farmers to work on the farms