Question

______ the fog, we should have reached the top of the hill.

1. A.
   In spite of
2. B.
   If there were no
3. C.
   But for
4. D.
   Because of

Answer 1

C
but for意为“要不是”，表示虚拟语气。句中的but for the fog=if it had not been for the fog。