根据短文内容填空。
My grandfather is already sixty years old. But he has only fifteen birthdays. Do you know why?
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.An interesting______.
2. My grandfather is______years old.
3. He has only______birthdays.
4. His birthday is on______
5. A leap year happens(发生)every ______ years.
1. birthday 2. sixty 3. fifteen 4. February 29th 5. four