从方框内选择合适的句子完成对话。

A. Thank you for your help. B. The blue pen is his. C. Is that yours? D. It's Helen's E. No, they are Bob's.

Teacher: Good morning!

Lisa: Good morning!

Teacher: Lisa, are these your books?

Lisa:

Teacher: And is this green pen his?

Lisa: No. it isn't.

Teacher: What about the dictionary?

Lisa: And the green pen is hers, too.

Teacher: And the pencil?

Lisa: Yes, it is.

Teacher:

Lisa: You are welcome.