根据对话内容，从A—E中选择适当的句子填空，使对话完整、通顺。(5分)
A: Good morning, Gina!
B:_____
A: Gina, is this a math book?
B:______ It’s Eric’s. But where is my math book?
A: Your math book? _______
B: Oh..., yes. Thank you.
A: _____
B: OK. Here you are!
A: ______