题目

阅读理解 What will you do when you have something difficult to do? I used to ask my mother for help. But she always said, “Do it yourself, dear.” I was not glad at all. I thought she was the laziest mother in the world! For example, one day, I decided to invite some friends to my home. My bedroom was not in order. Books were everywhere. And I didn’t make the bed. I asked my mother to help me to clean it, but she still said, “Do it yourself, girl.” Because of my “lazy mother”, I have to wash my clothes and clean my room. I have to help my parents do some housework. I e（2012?鼓楼区一模）（1）请根据平面镜成像特点作出图中物体AB在平面镜中所成的像A′B′．（2）生活中一些看似平常的工具却蕴含着丰富的物理知识，如图所示的夹钳就是其中一例，它在工作时可视为杠杆，试画出其中AB部分在夹物体时的动力臂l1和阻力F2．（3）如图所示，是开关闭合后，小磁针在条形磁体和通电螺线管的共同作用下，在图中位置处于静止状态，请你根据小磁针的指向，在图中标出条形磁铁的极性和通电螺线管的电源的正、负极．