问题补充：
--Have the police found the parents of the baby found by the road?
---Not yet. His identity .
A. would be found out
B. has been found out
C. is being found out
D. had been found out
答案：
A. would be found out
B. has been found out
(答案→)C. is being found out
D. had been found out
解析：考查时态：句意是;--警察找到路边发现的男孩的父母了吗？--还没有，他的身份正在核实。说明用现在进行时的被动语态，选C。
