1, rice, millet and wheat grains are collectively referred to as five grains. There are two main types: one refers to rice, millet, millet, wheat and rice grains. The other refers to hemp, millet, millet, wheat and glutinous rice. The difference between the two is that the former has rice without hemp, while the latter has hemp without rice. The ancient economic and cultural center was in the Yellow River Basin, and the main rice producing area was in the south, while the rice planting in the north was limited, so there was no whole grain rice at first.

2. Grains were originally called grains in ancient China, and later referred to food crops in general. There are two main views about grain. The mainstream is rice, commonly known as rice, rice and millet, commonly known as yellow rice and millet, also known as millet, commonly known as millet and wheat, commonly known as wheat, used to make flour, while glutinous rice is commonly known as soybean. Because the dry climate in some places is not conducive to the cultivation of rice, hemp is used instead of rice as one of the five grains.