Question

He’ll never forget the years _______ he studied in Oxford University

1. A.
   where
2. B.
   on which
3. C.
   when
4. D.
   which

Answer 1

C
考查定语从句。句中先行词为the years在从句中作时间状语，故用关系副词when。句意：他将永远不会忘记他在牛津大学学习的那些年。