After the arrival of hunter-gatherers in the southwestern region of North America, several alternative types of agriculture emerged, all involving different solutions to the Southwest’s fundamental problem: how to obtain enough water to grow crops in an environment in which rainfall is so low and unpredictable that little or no farming is practiced there today.

(1) all involving different solutions to the Southwest’s fundamental problem 做什么成分？独立主格？还是同位语？

(2) how to obtain enough water to grow crops 做什么成分？是同位语吗？

(3) that little or no farming is practiced there today 做什么成分？结果状语从句？

【答】

(1) all involving different solutions to the Southwest’s fundamental problem 做什么成分？独立主格？还是同位语？

——这是分词独立主格结构，作emerged的结果状语。all是独立主格的逻辑主语，又指代前文的several alternative types。

(2) how to obtain enough water to grow crops 做什么成分？是同位语吗？

——与前文的problem，具有内容或解释关系，应视为同位语。

(3) that little or no farming is practiced there today 做什么成分？结果状语从句？

——是结果状语从句。主句含有程度副词so，that从句为结果状语从句。

解答完毕！