—Eric, isn’t this book yours?—Yes, it used to belong to _________, but from now on it isn’t. 

I can’t find my pen. Could you help ________ find it?

--- Who is the woman in black?--- ________ is our physics teacher.

---Do you know        this dictionary belongs to?---Let me see. Oh, it's       .

 —Whose books are these? —Maybe ________ Lucy’s.