Question

I don't understand ______ he said, so I don't know ______ do it．

1. A.
   what…what to
2. B.
   how…what to
3. C.
   what…how to
4. D.
   how…how to

Answer 1

C
“我不理解他所说的话”，用what he said．“我不知道怎么做”，用how to do it．