This is our classroom.（一般疑问句,肯定回答） Whose book is this?（复数句）

题目

This is our classroom.（一般疑问句,肯定回答） Whose book is this?（复数句）
They's his pants.（一般疑问句,否定回答）
Our chairs are (under the desk.)就划线部分提问
I have a black pen.（用he改写句子）

答案

Is this your classroom?
Yes it is
Whose books are these?
Are they his pants?
No they aren't
Where are your chairs?
He has a black pen