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