根据句子提示填空。 1. —Is this your pen? —Yes, _
题型：填空题
问题：
根据句子提示填空。
1. —Is this your pen?
—Yes, ________ is.
2. —Is she your mother?
—No, ________ isn't.
3. Mr. Green teaches me English. ________ is my English teacher.
4. —Are you a teacher?
—Yes, ________ am.