A: Hello, Ben. I need to make a survey （调查） about the average age of our class. Can you tell me what is the date of your birthday?

B: OK. My birthday is on the third of May, 1996 .

A: The third of May, 1996. （记录在纸上） Thank you.

A: Hi, Sally. I need to make a survey （调查） about the average age of our class. Can you tell me what is the date of your birthday?

C: No problem. I was born on the twenty-first of July, 1996 .

A: The twenty-first of July, 1996 . （记录在纸上） Thank you.

... ...

A: OK. Now I can calculate the average age of my class.