---My pen is missing. I can’t find it anywhere.

---I’m afraid you have to buy _________.

A. it                            B. one                        C. any                          D. few

This is ______ my pen. I’m writing with _____ pen.

A．the, /             B．/, the             C．a, an             D．an, /

This is ______ my pen. I’m writing with _____ pen.

This is ______ my pen. I’m writing with _____ pen.

This is ______ my pen. I’m writing with _____ pen.

A．the, /             B．/, the             C．a, an             D．an, /