从方框里选出合适的语句，填入对话中，使对话通顺、完整。

A:      1    

B:  Hi, Billy.

A:     2    

B: I have been to the shops. Look, I bought this hat.

A:  It's pretty.   3  

B:  No, I didn't.

A:  Where has she gone?

B:     4    . She will be back at about five o'clock.

A:      5     She has been to the park every day this week.

B:  That's because she plays tennis there.

A.  To the park again?

B.  Hello!

C.  Did you go with Jenny?

D.  She has gone to the park.

E.  Where have you been

有两个共点，力的大小分别为9N、12N，两力的夹角为90°，则此两个力的合力为（）N。

A.3

B.15

C.21

D.30