“时间都去哪了？还没有好好感受年轻就老了，生儿养女一辈子，满脑子都是孩子哭了笑了……”真实普通的歌词却感动了全国上下。作为子女报答父母应（    ）

①从生活的点滴做起，从现在做起     ②听取父母的意见和教导

③倾听父母的心声                                 ④满足父母的一切要求

如图所示，轻弹簧上端固定，下端悬挂一质量为m的条形磁铁，磁铁穿过固定的水平闭合金属线圈．将磁铁托起到弹簧压缩x后由静止放开，磁铁会上下运动并逐渐停下来，静止时弹簧伸长x．不计空气阻力，重力加速度为g，弹簧始终在弹性限度内，则（   ）

    I'm Peter. There are four people in my family. They are my father, my mother, my grandfather and me. I'm twelve. My birthday is on 15th March. My parents are both doctors. They help people. Their birthdays are both in May. My grandfather is old. He is sixty-five. His birthday is on 9th June. He likes reading. I like reading too. I want to be a teacher in the future. I want to teach Chinese in a school.

2013年10月30日，中国最大淡水湖鄱阳湖出现严重低枯水位。其最主要的原因是（   ）