There was a time ＿＿ Tom was interested in music.A. which B. on which C. what D. when

问题补充：

There was a time ＿＿ Tom was interested in music.

A. which

B. on which

C. what

D. when

答案：

A. which

B. on which

C. what

(答案→)D. when

解析：从句修饰time（名词），因此是定语从句，从句主干完整，time 在从句做时间状语，使用关系副词，因此填when 或during which, B选项介词不对。