如图所示电路中，小灯泡L标有“6V3W”字样，R₂=12Ω，当S₁、S₂都闭合时，总电流为0.8A，这时小灯泡L正常发光．求：

（1）电源电压U；

（2）电阻R₁的阻值；

（3）当S₁、S₂都断开时，小灯泡L消耗的功率．

—Could you tell me _____?

—Certanily. In half an hour. [ ]

A. when will the high speed train arrive        

B. when the high speed train will arrive      

C. when would the high speed train arrive      

D. when the high speed train would arrive