Primary production involves acquiring raw materials. For example, metals and coal have to be mined; oil drilled from the ground; rubber tapped from trees; foodstuffs farmed, and fish trawled.

• 初级产品涉及获取原材料。例如,金属和煤无疑是被开采出来的;石油则必须是从地下钻取出来的;橡胶必须是从树木上被割取下来的;食品和鱼类则是分别被耕作与打捞所得的。