--Mum，Mary bought a parrot yesterday，Could you please buy ________ for me?

--Sure，But you must take good care of it．

A．one                     B．this                      C．it                           D．that

-- Mum, Mary bought a pet dog yesterday. Could you please buy __________ for me?
-- Sure. But you must look after it yourself.

-- Mum, Mary bought a pet dog yesterday. Could you please buy __________ for me?

-- Sure. But you must look after it yourself.

-- Mum, Mary bought a pet dog yesterday. Could you please buy __________ for me?
-- Sure. But you must look after it yourself.

1. A.
   that
2. B.
   this
3. C.
   it
4. D.
   one