小球从离水平地板3m高处沿竖直方向自由下落，被水平地板弹回，在离水平地板2m高处被接住，共用时间1.25s，则在这个过程中小球的平均速率和平均速度的大小分别是（　　）

A: Hello, Lisa. Nice to meet you.

B: Hi, Leila. Nice to meet you, too.

A: ____.

B: I'm thirteen. What about you?

A: Fourteen, ____

B: It's March 5^th. And you?

A: ____

B: Oh, it's coming soon. ____

A: Yes, I do. Can you come to my party?

B: ____. Thanks

A. How much is it?

B. How old are you?

C. Happy birthday!

D. When is your birthday?

E. My birthday is January 10^th.

F. Yes, I'd love to.

G. Do you want to have a birthday party?

如图，在⊙O中，弦BC=1，点A是圆上一点，且∠BAC=30°，则⊙O的半径是 ____．