问题补充：
---Which of the following sentences is CORRECT?
A. I don’t know when will he come back tomorrow.
B. I have no idea when will he come back tomorrow.
C. I don’t know when he will come back tomorrow.
D. I have no idea when is he coming back tomorrow.
答案：
A. I don’t know when will he come back tomorrow.
B. I have no idea when will he come back tomorrow.
(答案→)C. I don’t know when he will come back tomorrow.
D. I have no idea when is he coming back tomorrow.
解析：句意：下面哪一个句子是正确的？我不知道他明天什么时候回来。宾语从句中用陈述句的语序，同时根据本句中的时态可知应该为一般将来时态，故为C
