Methods: The stratified sampling and cluster random sampling methods are used in this survey.
方法：本研究采用分层随机抽样方法和整群随机抽样方法。
RESEARCH METHODThe stratified multi-stage cluster random sampling method was used in the survey.
研究方法本研究采用分层整群随机抽样方法进行抽样。
Methods Cluster random sampling was used for investigation of 39 villages selected from 13 counties.
方法采用分层整群随机抽样的方法，对13个中签县市39个村(点)进行调查。
应用推荐