Analysis of the test questions: ① ④ The option is correct and in line with the meaning of the test questions. The commemorative coin in the test questions is brass alloy, which is valuable and can be circulated with RMB of the same denomination in equal value, and can perform the functions of value scale and circulation means, so it is selected. ② ③ The option view is wrong. Commemorative coins are brass alloys, which are valuable in themselves. They can be used not only for collection, but also for circulation in the market. Their purchasing power is determined by the market, not by the People's Bank of China, so they are excluded.