题目选项分析

At the turn of the twentieth century, forest covered as much as 90 percent of Thailand and accommodated as many as 300,000 elephants, a third of them domesticated and performing various essential tasks.

At the turn of the twentieth century, forest covering as much as 90 percent of Thailand accommodated as much as 300,000 elephants, and a third of them were domesticated and performing various essential tasks.