根据短文内容填空

     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.

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.

蛛网膜下腔出血与脑出血鉴别，下列哪项最重要（）

A.活动中发病

B.头痛、呕吐

C.脑脊液含血量多少

D.发病后出现偏瘫、失语等

E.脑膜刺激征