China, a large - scale survey in 2007 found that 20 % of men with erectile dysfunction and smoking.
2007年中国一项大规模调查还发现,20%的男性勃起功能障碍与吸烟有关.
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Methods A large - scale survey was conducted at 250 medical health units based on stratified sampling.
方法使用分层抽样的方法在全国范围内抽取250家医疗机构开展大规模调查.
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