如图是一圆柱形输水管的横截面，阴影部分为有水部分，如果水面AB宽为8cm，水面最深地方的高度为2cm，则该输水管的半径为（　　）

A. go to see him         

B. have a lot of fun

C. under the tree                    

D. at Christmas

E. a Christmas tree                

F. buy presents

G. a turkey and Christmas puddings

A:What do you do ____?

B: First, we ____ for our family and friends. We need to buy____.We put our presents ____.It looks great.

A:What do you like best at Christmas?

B:I like Father Christmas. We sometimes ____.

A:What do you eat that day?

B:I eat ____ .

A:So you ____at Christmas.

1千克面粉可磨面粉0.8千克，50千克小麦可磨面粉____千克。