根据对话内容及所给首字母提示，补全所缺单词。使对话完整、通顺

A: Morning, Jackie! How was your vacation in the countryside?

B: W! I had fun and met a new friend.

A: Is she a girl?

B: Yeah! Her name is Grace.

A: Grace? I know her. She's Bob's sister. She is tin music.

B: Wow! Really?

A: Yeah! She is good at singing. She took part in (参加) many singing cand won lots of prizes.

B: But her brother Bob's songs sound beautiful, too. Who do you think sings b, Bob or Grace?

A: Oh I think Bob sings as was Grace. They are both great singers.