从A、B、C和D四个选项中，选出可以填入空白处的最佳选项。
21. Beijing is most famous capital, and city which has become the center of politics and culture in China.
A. a; / B. the; the C. the; a D. a; the
22. Ever since its appearance over two decades ago, the Spring Festival Gala has developed into
most Chinese find it hard to ignore.
A. where B. what C. that D. when
