——Where did you come across our chemistry teacher ?

------ It was in the supermarket ______ I purchased mooncakes.

A. that             B. which           C. where                D. when

——Where did you come across our chemistry teacher ?

------ It was in the supermarket ______ I purchased mooncakes.

that             B. which           C. where                D. when

---Where did you come across our chemistry teacher ?

       --- It was in the supermarket ______I purchased mooncakes．

       A．that         B．which          C．where       D．When

——Where did you come across our chemistry teacher ?

------ It was in the supermarket ______ I purchased mooncakes.

A. that             B. which           C. where                D. when

---Where did you come across our chemistry teacher?

--- It was in the supermarket ______ I purchased mooncakes.

A. that           B. which           C. where       D. when