Methods Stratified sampling methods were used to carry out the prevalencestudy of maternity and child care for women at child bearing-age in Luochuan County and Bin County.
方法采用分层抽样，抽取洛川、彬县育龄妇女入户进行妇幼保健现状问卷调查。
2
One large scale study in Maryborough, Victoria, Australia showed the prevalence of mid-frontal baldness increases.
在澳大利亚维多利亚州马里伯勒进行的一项大规模研究表明，中额秃顶的患病率呈上升趋势。
3
However, no study on the prevalence of infertility has been conducted in this area.