A、More than twenty years. B、Nearly ten years. C、Nearly forty years. D、Nearly thirty years. C录音原文提到Today，after nearly forty years

The banking system of China evolved from a mono-banking system between the 1940s and the early 1970s. Not until 1978 did China’ s banking system make a drastic shift in its banking philosophy and structure. The shift is not only a necessity for the country’ s development, but also acts as a gesture showing the "openness" of the country to the outside world.
    Today, after nearly forty years of rapid development, China is moving towards a modern and market-oriented banking structure although there is still much to be improved to meet the needs of the country’ s development.
    In the mid 1990s, banks in China began to focus their attention on capital adequacy requirements , non-performing and bad loans, profitability and also the industry’ s overall expansion strategy. Reforms of monetary and financial system in China are speeding up in the 90s. Existing specialized banks gradually have become commercial banks.
21. What kind of banking system did China have before the 1980s?
22. Up to now, how long has China experienced rapid development?
23. What are the banks in China focusing their attention on?