I had to report the accident _______ length as the reporter asked me to describe it _______ detail.

   A. in, in                  B. at, in               C. at, at                D. in, at

I had to report the accident ________ length as the reporter asked me to describe it ________ detail．

1. A.
   in; in
2. B.
   at; in
3. C.
   at; at
4. D.
   in; at

I had to report the accident _______ length as the reporter asked me to describe it _______ detail.