the primary sector

劍橋詞典

industries that involve collecting and selling natural things, for example crops , rock , and wood , often in order for them to be made into something else
（采集和銷售自然產(chǎn)品如谷物、石頭、木材的）第一產(chǎn)業(yè)
比較
the secondary sector 返回 the primary sector