下列能展现长江流域居民制作末耜、种植水稻等原始农耕生活图景的文化遗址是[ ]
A．元谋人遗址
B．北京人遗址
C．河姆渡遗址
D．半坡遗址
答案：C
第三方物流采购的一般过程是什么？
Which of the following most accurately describes the condition that typically exists when marginal product is at a maximum（）
A. Marginal cost is at a minimum.
B.Average product is at a minimum.
C.Average variable cost is increasing.
