题目

阅读理解 If you had a strange sound in your ear, what would you do? One man in Wales who thought he had a fly in his ear called 999, the emergency services number in Britain. And so did a woman who was worried about her green potatoes. Could she make chips with them? Were they poisonous? She didn't hesitate about calling the local ambulance service to ask. According to a recent report, more than 31,000 non-urgent calls were made to the Welsh Ambulance Service in the last year. Inappropriate calls are a headache for health professionals everywhere. In the US, prank calls to 911 happen on a 如图所示，用电流传感器研究自感现象．电源内阻不可忽略，线圈的自感系数较大，其直流电阻小于电阻R的阻值．t=0时刻闭合开关S，电路稳定后，t1时刻断开S，电流传感器连接计算机分别描绘了整个过程线圈中的电流IL和电阻中的电流IR随时间t变化的图象．下列图象中可能正确的是（ ）