重新排列以下句子的顺序，使它们组成一段通顺的对话。
A. Oh, yes, it is. It's in the book. Thank you.
B. No, it isn't.
C. That's all right.
D. Excuse me, where's my ruler? Do you know?
E. No, I can't see it.
F. Is it in your math book?
G. Oh, sorry, I don't know. Is it in your pencil case?
H. Is it in your desk?
1. 2. 3. 4. 5. 6. 7. 8.
