因此，不可能建立人口和健康群组。

Therefore, it was not possible to establish a demographic and health cohort.

youdao

由专业女性研究人员在预先测试过的研究表格上记录人口和健康数据。

Demographic and health data were also collected on pretested study forms by trained female research staff.

youdao

前瞻性人口和健康群组是评估儿童死亡率和其他人口指标的最准确方法。

Prospective demographic and health cohorts are the most accurate method to assess child mortality and other demographic indices.

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