题目选项分析

The large populations and impressive cultural achievements of the Aztecs, the Mayas, and the Incas could not have come about without corn, which was not only nutritious but also it could be dried, transported, and stored for long periods.

The large populations and impressive cultural achievements of the Aztecs, the Mayas, and the Incas could not have come about without corn, which not only was nutritious but also could be dried, transported, and stored for long periods.