-- Mum, Mary bought a pet dog yesterday. Could you please buy for me?
-- Sure. But you must look after it yourself.
A. that
B. this
C. it
D. one
网友回答
A. that
B. this
C. it
(答案→)D. one
解析：本题题干的意思是“你能给我买一只吗？”此处的代词应该表示泛指“一个”的意思。而that、this和it所在的对象都是一定的。故只能用one来表示泛指“一个”。所以本题选D。