缩小的国家：塞尔维亚与人口下降作斗争

ghost – n. a very small amount or trace (as in ghost town, a town with few remaining inhabitants)

migration – n. movement from one area to another

mission – n. an important job or duty

sanction – n. a threatened punishment for disobeying a law or rule

tend – v. used to describe what often happens or what someone often does or is likely to do — followed by to + verb

motivated – adj. describes someone who has a strong reason for doing something

drain – n. a thing that uses up something; the continued loss of something

challenge – n. a call to take part in a competition

demography – n. the study of changes (such as the number of births, deaths, marriages, and sicknesses) that take place over a period of time in human populations also : a set of such changes