题目

     All students have to face their own problems when they are growing up. You may not think that having a good family is a problem. But for me, it was. I had to face the problem of being the youngest of the Smith girls.      We live in a small town in Pennsylvania, US. There are three girls in the Smith family, Amanda, Theresa and me. People often say things to me, like Oh, the three of you, you' re such nice girls. Your sisters are so pretty and so thin! You' re really nothing like them. That made me sad.      At school, all of my teachers had taught my sisters. On the fi韦聪同学为了探究浮力的大小跟什么因素有关，他做了图所示的实验． （1）从图①②③可以得出：浮力的大小与________有关． （2）图③中物体受到的浮力大小为________N．