Only when ____ possible to settle the problem how to get the machine repaired. [ ]

A. does the monitor come will it be

B. the monitor comes will it be

C. has the monitor come it will be

D. the monitor comes it will be

下列说法不符合质量守恒定律的是（　　）

A．镁条在空气中燃烧后，生成物的质量比镁条的质量增加了

B．木炭燃烧后，留下的炭灰的质量比木炭的质量减少了

C．2 g氢气与 8 g氧气反应生成了 10 g水

D．8g氢气与8g氧气反应生成了9g水