Refer to Figure 12.1. Six firms that produce chewing gum have formed a cartel. The cartel faces the market demand curve given by D. To maximize profits, the cartel should produce ________ packs of chewing gum and the price should be ________.
【单选题】听力原文: There are over 6,000 million people in the world today, and the total is increasing at the rate of more than 89 million a year. The population is growing more quickly in some parts of the world ...