题目:
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 was able to be dried, transported, and stored for long periods.
选项:
A、which was not only nutritious but also was able to be
B、which not only was nutritious but also could be
C、which was not only nutritious but also it could be
D、not only nutritious but it could also be
E、not only nutritious but also able to be
答案:
B