选择合适的句子补全对话。

Grandma: There was no park in my old town

Meimei: Oh,

Grandma: Yes, I could. I always saw the moon then.

Meimei: Tell me about your school, please

Grandma: There was no gym in my school fifty years ago.  

Meimei:

Grandma: Ah?

Meimei: It's easy. Haha...It's a secret.

A. There was no Internet in your time. B. could you see the moon at night? C. How do you know that? D. There is a big gym in my school. E. There was only one small building in this town.