thae is my pen.that is his desk.this is her pen-case.that is your eraser.改成一般疑问句并做回答

1.Is that your pen?Yes,it is./No,it isn't.2.Is that his desk?Yes,it is./No,it isn't3.Is this her pen-case Yes,it is./No,it isn't4.Is that your eraser?Yes,it is./No,it isn't