A:1:1
B:1:2
C:2:1
D:无法确定
如图1所示是电阻R1与滑动变阻器R的电路图,电源电压为12V,电阻R1的I﹣U图象如图2所示.开关闭合后,滑动变阻器R接入电路的阻值为40Ω时,求:
-- Such beautiful flowers! I can't decide _______ for my mum.
-- For Mother's Day, it can't be better to take some carnations (康乃馨).
泊秦淮
杜牧
烟笼寒水月笼沙,夜泊秦淮近酒家。
商女不知亡国恨,隔江犹唱后庭花。