Question

—      you        who took my pen by mistake?

—Not yet.

1. A.
   Did; find
2. B.
   Did; find out
3. C.
   Have; found out
4. D.
   Have; found

Answer 1

C
由Not yet的答語(yǔ)可知應(yīng)用現(xiàn)在完成時(shí),find out是“查明”，此句的含義是你能查明是誰(shuí)錯(cuò)拿了我的鋼筆嗎。