---What is he going to when he up?---He’s going to be a doctor.A. do growB. do growsC. b

问题补充：

---What is he going to when he up?

---He’s going to be a doctor.

A. do, grow

B. do, grows

C. be, grow

D. be, grows

答案：

A. do, grow

B. do, grows

C. be, grow

(答案→)D. be, grows

解析：本题考查的是when 引导的时间状语，在这个时间状语中，当主句为一般将来时，从句用一般现在时来代替将来时，故选D