根据首字母提示和实际情况填空。
1. Beijing is the c__________ city of China.
2. — What color is China’s flag? 
— It is r__________. 
3. How many stars does it have?  It has f__________ stars.
4. — What colour are the stars? 
— They are y__________.
5. We live in C__________ .We speak C__________.