如图所示，电源电压保持不变，灯泡L标有“6V 6W”字样（灯丝的阻值不变），当S和S₁都闭合时，电压表示数为10V；当闭合S，断开S₁时，灯泡L正常发光．求：

①电阻R的阻值．

②当闭合S，断开S₁时，电路消耗的总功率．

    Do you know about Xiong'an? It's a new city near Baoding. There is a big lake in Xiong'an. Yes, it is Baiyangdian Lake. It is very big. In summer, you will see many beautiful lotus flowers on the lake. Some are red. Some are pink. Many people like them. There will be many boats on the lake. And there will be many birds singing in the grass. Xiong'an is beautiful and new. You can come here by bus from Baoding. And you can come here by train. You will play in the water with your friends. You will eat delicious fish. You will take many wonderful pictures. You will have a nice trip in Xiong'an.

北京围绕故宫一带的市中心不是中央商务区，而是行政区，其原因是（    ）