【单选题】One bag of flour is sold for $1.00 to a bakery, which uses the flour to bake bread that is sold for $3.00 to consumers. A second bag of flour is sold for $1 to a grocery store who sells it to a consu...
【单选题】There are two industries, flour and coffee, when their market size grows by the same percentage, the increase of the change of the number of firms in the flour industry is ___ than that of the firms i...