The greatest risk occurs in overpopulated communities and refugee settings characterized by poor sanitation and unsafe drinking water. 最大的危险存在于以卫生设施不良和饮用水不安全为特点的人口过密的社区和难民居住地。
A. An overpopulated earth will be unable to sustain its inhabitants. 人口过剩的地球无法维护它上面的居民。
