Question

________ have you been ________ I saw you last time?

1. A.
   Since, where
2. B.
   When, where
3. C.
   Where, since
4. D.
   While, as

Answer 1

C
时间状语从句典型题例since是连词引导时间状语从句“自从……以来”常与现在完成时搭配，根据题意应选C。