A、1992 B、1993 C、1994 D、1995 C录音原文提到China has maintained a unified managed floating exchange rate since January 1994，中国从1994年1月开始

The Chinese currency is the Renminbi. China has maintained a unified managed floating exchange rate since January 1994. The exchange rate of the Renminbi is determined by the inter-bank foreign exchange market. The People’ s Bank of China announces a reference rate for the Renminbi against the US dollar, the Hong Kong dollar, and the Japanese yen based on the weighted average price of foreign exchange transactions during the previous day’s trading. Daily movement of the exchange rate of the Renminbi against the US dollar in inter-bank foreign exchange market is limited to 0.3% on either side of the reference rate as announced by the PBC. The buying and selling rates of the Renminbi against the Hong Kong dollar and the Japanese yen may not deviate more than 1% on either side of the reference rate. In the case of other currencies, the deviation may not exceed 0.5% on either side of their respective rates.
21. When did China begin to maintain a unified managed floating exchange rate?
22.Who determines the exchange rate of the Renminbi?
23.What is the deviation allowed on daily movement of the exchange rate of Renminbi against the US dollar?