“When _____ he come？” “I don’t know, but when he _____, I’ll tell you.”

A．does, comes

B．will, will come

C．does, will come

D．will, comes

有一金999手镯，门头因工艺需要含金量为金900。因此，除了镯身上应打上千足金印记之外，门头上也应打上（）的印记。

A.金900

B.Au999

C.Pt900