The cluster sample method is most often used because, in the initial stages of emergencies, people are rarely living in a structured pattern.

分组抽样方法是最常用的，因为在紧急情况的初期，人们很少住在有组织的环境中。

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The cluster sample method is most often used because, in the initial stages of emergencies, people are rarely living in a structured pattern.

分组抽样方法是最常用的，因为在紧急情况的初期，人们很少住在有组织的环境中。

youdao