甲、乙两人接到编织一张羊毛毯的订单，若甲单独编织需要35天，乙单独编织需要25天。现由甲编织第一天，从第二天起每天均由上一天未编织的人编织。问当地毯编织完成一半时，乙编织了几天？

A．many firms that produce a homogeneous product
B．many firms that produce slightly different products that are close substitutes
C．such a small number of firms that each must figure out how the others will respond to its own actions
D．one firm, with no competitors, that produces a product with no close substitutes

A.间接标价法
B.美元标价法
C.直接标价法
D.应收标价法

A. 11
B. 12
C. 13
D. 14