问题
单项选择题
Which of the following is NOT a condition of a perfectly competitive market（）
A. Sellers make economic profits.
B. Firms face elastic demand curves.
C. Individual sellers each have a small share of the market.
答案
参考答案：A
解析：
The only item listed that is not a condition of a perfectly competitive market is that sellers make economic profits. In fact, sellers do not make economic profit after taking into account their opportunity costs.