题目

The 16th Asian Games       in Guangzhou from November 12 to November 27，2010．        A．was held                                             B．was holding            C．will be held                                             D．will be holding 答案：C 以下是“描绘小灯泡的伏安特性曲线”实验的操作步骤：                                                A．闭合电键，记下电流表、电压表的一组示数（I，U），移动变阻器的滑动触头位置，每移动一次记下一组（I，U）值，共测出12组左右的数据．                                                                                           B．将电流表、电压表、变阻器、电灯、电源开关正确连成电路，电流表外接，变阻器采用分压式，如图所示                                                                                                                                         C．调节触头位置，使闭合电键前触头处于变阻器的左端．                                         D．按所测数据，在坐标纸上描点并将各点用直线段连结起来，得出小灯泡的伏安特性曲线．                                                                                                                                          （1）以上各步骤中存在错误或不妥之处的是                                            ，应如何改正                 ？                         （2）将步骤纠正后，按实验先后顺序排列起来                          ．