Methods. The survey was conducted according to multi-stage stratified cluster sampling method.
方法：分阶段分层整群随机抽样调查。
After a lot of survey and careful design work, a one-dimensional test system with multi-function such as air stage and fuel reburning is built up.
本文经过大量的调研和仔细的设计、完善，建成了具有空气分级、燃料再燃等多种用途的一维热态试验系统。
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。
Method A multi-stage stratified cluster sampling survey on health condition of 14486 residents was taken in 2007.
方法：采用多阶段分层整群抽样方法，对2007年居民家庭健康状况入户调查，共调查14 486人。
Method A multi-stage stratified cluster sampling survey on health condition of 14486 residents was taken in 2007.
方法：采用多阶段分层整群抽样方法，对2007年居民家庭健康状况入户调查，共调查14 486人。
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