定義： A tract of crop or grazing land, as well as the group of buildings with and often surrounding a farmhouse, including barns, sheds, and other outbuildings, used for agricultural production.
定義： A grassland biome is a terrestrial biome which includes, across its entire spatial extent, an unbroken layer of grasses (Gramineae), sedges (Cyperaceae) or rushes (Juncaceae).
