Question

Was it in the factory_____ you worked five years ago___ you learned the technique?

1. A.
   that; where
2. B.
   where; when
3. C.
   where; where
4. D.
   where; that

Answer 1

D
从整个句子来分析，本题的主干是Was it in the factory_____ you worked ___ you learned the technique?这一强调结构，you worked five years ago 是定语从句，限定the factory。