题目选项分析

A study concludes that the Indus civilization, which existed 6,000 years ago, experienced violence and disease of such severity

that they eroded the ability of the population to stay in their cities, and resulted in being unable to remain

A study concludes that the Indus civilization, which existed 6,000 years ago, experienced violence and disease of such severity

that they eroded the ability of the population to stay in their cities and, as a result, to remain