手电筒内装有4节新的干电池，已知灯丝的电阻为10Ω，则通过它的电流为    。若时间久了，电灯亮度减弱，经测量流过灯丝的电流为0.4A，则此时电源电压为     V.

--- Did the book give the ___________ you needed?

--- Yes. But ____________ it, I had to read the whole book.

A．information; find

B．information; to find

C．message; found

D．message; finding