________ is often the case, we have worked out the production plan．

1. A.
   Which
2. B.
   When
3. C.
   What
4. D.
   As

_______ is often the case, we have worked out the production plan.?

A. Which B. When?

C. What D. As?

________ is often the case, we have worked out the production plan.

     A. Which               B. When                C. What               D. As