题目

 If I ______ten years younger, I _____ very happy. A. am, would be   B. am, shall be   C. were, shall be   D. were, would be 答案：D8．如图甲所示的电路，电源电压恒定，其中R2=10Ω，开关闭合时两只电流表的指针恰好指在同一位置处，电流表指针如图乙所示，则电源电压为16V，R1=40Ω．