【题目】— Where did you learn how to plant flowers?
— It was on the very farm ___ we once worked.
A.that
B.which
C.what
D.where

【答案】D
【解析】考查定语从句。句意：你在哪里学的种花？就在我们曾经工作的农场里。根据句意及句子结构分析可知，此处为定语从句，先行词是the very farm，连词在从句中作地点状语，应使用关系副词。故选D。