根据下面的对话情景．在每个空白处填上一个适当的句子、使对话的意义连贯、完整。
A: Hello! May I speak to Bruce?
B: _____小题1:_____________.
A: Hi, Bruce. This is David. I haven't seen you for a long time.__________小题2:_____________?
B: I have been to Shanghai. I came back this morning.
A: Really? _________小题3:_________?
B: I went there with my parents. We had a wonderful time there.
A: ___________小题4:____________?
B: We visited the World Expo Park. We also went to the Oriental Pearl Tower and toured the Huangpu River.
A: _________小题5:___________?
B: Sure. The World Expo 2010 started on May 1st, 2010 and it will end on October 31st, 2001. People can see different countries' pavilions and experience different cultures without going abroad. If you miss this chance, you will regret.
A: I hope I 
can have a chance to visit the World Expo 2010 Shanghai during the summer vacation.
B: I hope so.
