on, in front of, under, next to

— The cow is .

— The dog is .

A: is your mother?

B: She is  the car.

A.     B.    C.   D.  

— Hi, Jack. What are you looking for?

— My new pen. I can't find it.

— Is it under your books?

— No, it isn't here.

— Is it in your desk?

— No, it isn't in the desk.

— Maybe it's in your bag.

— No, it isn't.

— Well, I think you should talk to the teacher. She can help you.