在房地产纠纷的解决方式中，仲裁区别于诉讼及行政处理的根本特征是( )
A．及时
B．公正
C．自愿
D．经济
参考答案：C
阅读理解。
The old man is already sixty years old. But he has only fifteen birthdays. How is it? When is his
birthday?
Keys: His birthday is on February 29th. It’s a leap(闰年) year every four years. So he has only
fifteen birthdays.
根据短文内容填空:
1. The old man is _______ years old.
2. He has only ________ birthdays.
3. His birthday is on _______.
4. A leap year happens(发生) every _______ years.
已知圆C的极坐标方程为ρ=-4sinθ+cosθ，则该圆C的直角坐标方程为______，圆心的直角坐标为______．
