Does non-staple food include noodles, rice noodles and river noodles? Does the staple food mean rice? Is mung bean a non-staple food?

First question, noodles are not non-staple food.

The second question is that staple food not only refers to rice, but also includes food made from whole grains, which can be called staple food.

The third question is that mung beans are not non-staple food, but miscellaneous beans.

Grains in the north can be made into various staple foods.