根据下面的对话内容，填出恰当的表达，使其意思通顺、合理、结构完整。
A：____1___?
B：Yes．I want to ____2____ some tickets for the concert next week．
A：How many tickets do you want?
B：Three．
A：___3____ performance（表演）do you like，Friday evening or Sunday afternoon?
B：Sunday afternoon will be fine．
A：Let me see．Ah，there happens to be ____4____ tickets left for Sunday's concert．
B：That's fine．I'll take them all．How much are they?
A：30 dollars each，90 dollars in all．
B：Here is 100 dollars．
A：OK．____5____，your tickets and the change．
B：Thank you．
1．What can I do for you／Can（May）I help you
2．buy 3．Which 4．three 5．Here you are