5. Those are erasers. (改为单数句)

                      eraser.

4. My CDs are in the drawer. (画线部分提问)

                        your CDs?

3. I have a pen. (改为否定句)

I                      a pen.

2. Is this a pen? (否定回答)

            ,                     .

1. That is a book. (改为一般疑问句)

                       a book?