There are four stages to the classical demographic transition model. pre-transitional europe was characterized by high and fluctuating mortality and a high birth rate. the transition model began to progress into and through stage 2 in the late 18th and early 19th century. all but one contributed to the decline in mortality. a) enacting measures to provide clean water supplies. b) public health advances including quarantine of settlements undergoing epidemics. c) the development of vaccines to prevent disease and antibiotics to treat infection. d) widespread acceptance of germ theory resulting in more hygienic practices, including hand washing and sterilizing medical equipment and infants’ bottles.