在如图所示的电路中，电池的电压为12V，滑动变阻器R的最大阻值是50Ω，电阻R₁的阻值为10Ω．当变阻器的P端从a端滑向b端时，电流表的变化范围是（）

根据图文资料，回答下列问题。

材料：今年的“中国桥梁”属于云南，龙江大桥、尼珠河大桥、普立特大桥……每座大桥的诞生都令无数人激动。近日，一座创造了三项“世界第一”建桥纪录的大桥实现了高精度合龙，它就是云南大瑞铁路（大理至瑞丽）上的澜沧江特大桥。

先通读下面的短文，掌握其大意，然后从A、B、C、D四个选项中选择可以填入空白处的最佳答案。

    On weekends，I don't need to go to school．I often go to1my grandfather,and he lives in a small town．

    It is a long way from my home to his home．Mick and Ted go2me．They are my cousins．Do you know how we go there? We ride our bikes there!We like3a lot．We start at nine o'clock in the morning,We4a lot of food and drink with us—bread ,milk,eggs and juice, 5we have lunch on the way．At about three o'clock in the afternoon,we6at the town．My grandfather is very7to see us．There is a park near his home，so he takes us to the8and we take a walk there．We9with my grandfather．The next day,we ride back home．We are tired (疲劳的)10very happy．