Grape, rice, pomegranate, silk, walnut, alfalfa and wheat, which are there in the Central Plains? Which ones were imported from the western regions?

Since Zhang Qian was introduced to the Western Regions, fine horses such as Tianma and Blood Horse, plants such as grapes, pomegranate, walnuts and alfalfa, musical instruments and songs and dances began to be introduced to the Central Plains. The techniques of cast iron, canal digging and shaft sinking in the Han Dynasty, as well as silk, lacquerware and metal tools, also spread to the Western Regions. Grape, pomegranate, walnut and alfalfa, these four kinds.