问题补充：
--- Tom wants to know.
--- I don know, either. He said he would phone me as soon as he came back.
A. when Dad comes back
B. when did Dad come back
C. when Dad will come back
D. when does Dad come back
答案：
A. when Dad comes back
B. when did Dad come back
(答案→)C. when Dad will come back
D. when does Dad come back
解析：句意：—Tom想知道爸爸什么时候回来。—我也不知道。他说他一回来就给我打电话。宾语从句的语序应该是陈述语序，排除B、D，因为它们是疑问句语序。A. when Dad comes back是一般现在时，C. when Dad will come back是一般将来时。本句表将来未发生的事，故选C。
考点: 考查宾语从句的用法。
