Question

---Hi, Joan, I haven’t seen you for ages．What ________ recently?

---Carrying on some research on wildlife．

1. A.
   did you do
2. B.
   have you done
3. C.
   were you doing
4. D.
   have you been doing

Answer 1

D
答句是个省略句，完全形式应为“I have been carrying on some research on wildlife．”。由此可知应用现在完成进行时。