阅读对话，根据上下文补全对话，使对话完整。
A：Hello，may I speak to David?
B: ____________________________ .
A: Hi, David! This is LinTao speaking.
B: Hi,LinTao.What’s up?
A: what are you going to do this Sunday?
B: ____________________________.
A: shall we go to the zoo?I hear there’s a dolphin show there.
B: A dolphin show? Good idea! ____________________________.
A: By bike.
B: _________________________________.
A: At half past nine.
B:_________________ ______________.
A: Let’s meet outside the zoo gate.
B: All right. See you then.