根据对话内容与上下文，在空白处填入适当的句子，使对话意思完整。
A: Hello, may I speak to David?
B: _________________________________________.(1)
A: Hi, David! This is Lin Tao speaking.
B: Hi, Lin Tao. What's up?
A: What are you going to do next Sunday?
B: _________________________________________.(2) Do you have any ideas?
A: Shall we go to the zoo? I hear there's a dolphin show there.
B: A dolphin show? Good idea! _____________________________________?(3)
A: By bike.
B: _____________________________________________________________? (4)
A: At half past nine. B: _____________________________________________________________? (5)
A: Let's meet outside the zoo gate.
B: All right. See you then.