Question

---Do you know _____ back tomorrow?
-  --Sorry, I don’t know. When he _____ back, I’ll tell you.

A．when does he come, comes	B．when he comes, will come
C．when he will come, comes	D．when will he come, will come

Answer 1

C

根据时间状语，上句问的是将来发生的事情，故用将来时态。主句为将来时态时，从句用一般现在时态，故选C。