题目

根据对话内容及方框中所给的选项补全对话。选项中有一项是多余的。（5分）( Li Lei is a Chinese exchange student in America. He is chatting with Jason in his host family. )Jason : Hi, Li Lei! Here is your juice.Li Lei: Thanks, Jason.Jason : Not at all.   【小题1】 Li Lei; That's right. How time flies!Jason :  【小题2】Li Lei; Yes, 1 do. The teachers are very helpful, and the students are active and confident.Jason : It's kind of you to say so. And I hear you Chinese students are very hard-working.Li Lei: We sure are.   【小题3】Jason : By the way,在探究加速度和质量的关系时，采用图甲所示的装置，小车用细线绕过长木板左端的定滑轮悬挂砝码盘，保持砝码盘和砝码的总质量不变，改变小车的质量m进行实验；（1）实验中，下列操作正确的是 ．A.电火花计器接交流电源B.使上部分细线与木板平行C.平衡摩擦力时，悬挂砝码盘和砝码D.平衡摩擦力时，将纸带连接在小车上（2）分别得到小车加速度a与质量m及其对应的 ，数据如表：实验次数123456小车加速度a/ms﹣22.001.801.491.000.750.50小车质量m/kg0.330.370.450.670.901.31小车质量的倒数m﹣1/kg﹣13.032.702.221.491.110.76请在如图乙所示的方格坐标纸中画出a﹣1/m图线，可得出结论是 ．