demographer

1. 人口学;人口统计学
   Demography is the study of the changes in numbers of births, deaths, marriages, and cases of disease in a community over a period of time.

1. The first to use it in its modern sense was Alfred Sauvy, a French demographer who drew a parallel with the "third estate"( the people) during the French revolution.
   首次使用现代意义上第三世界的是法国人口学家艾尔弗雷德·索雷（AlfredSauvy），法多大革命时期，他用第三世界来比喻“平民阶级”（第三阶级，thirdestate）。
2. Joel Kotkin, a demographer, points out that California has always had fires during dry years, at least since the time of the Spaniards.
   人口统计学家约尔·柯特金指出，加州在干旱年份总是有火灾，这至少始于西班牙人统治时期。
3. EarthSky spoke with Carl Haub, a demographer at the Population Reference Bureau, a Washington D.C.-based think-tank, about why the population is getting older.
   EarthSky就人口老龄化原因的话题采访了卡尔•霍伯。他是美国人口咨询局的一名人口统计学家，也是华盛顿智囊团的成员。
4. Demographer William Frey says immigrants with young families will help keep the United States competitive.
   人口统计学家佛瑞表示这些年轻的家庭会帮助美国保持竞争力。
5. John May, a demographer at the World Bank, warned: Each new billion will pose more problems than the previous billion.
   世界银行（worldbank）人口学家约翰梅（JohnMay）警告说：每新增10亿人口，都会比之前的10亿人口造成更多问题。
6. This was the grim fact identified by Thomas Malthus, an English demographer, that a country's economic potential was limited by its food supply.
   这就是英国人口学家马尔萨斯发现的可怕事实：一国经济之潜力受制于食品的供应。
7. The demographer will coordinate data collection and analysis on human settlements conditions.
   这个人口统计学家将会整合这些数据并分析人类的居住条件。
8. Zheng Zizhen, a demographer at the Guangdong Academy of Social Sciences ( GASS), says even a modest change would help.
   广东社会科学院的人口统计学专家郑梓桢说，即使是个激进的革新对现有情况的改动也很有协助。
9. Methods With the mode of disease fail initiated by the demographer Manton, K.
   方法采用人口学家Manton，K。

noun

1. a scientist who studies the growth and density of populations and their vital statistics

   Synonym:    demographistpopulation scientist