以下事例中所用的科学方法相同的是（　　）

（1）串联电路的总电阻概念 （2）探究浮力大小与物体排开液体体积的关系（3）曹冲称象 （4）把电流与水流做比较 （5）用磁感线表示磁场．

阅读下文，完成小题。

江南雨

汪国真

                                                                                                     江南也多晴日

                                                                                                     但烙在心头的

                                                                                                     却是江南的

                                                                                                     蒙蒙烟雨

                                                                                                     江南雨斜斜

                                                                                                     江南雨细细

                                                                                                     江南雨斜

                                                                                                     斜成檐前翩飞的燕子

                                                                                                     江南雨细

                                                                                                     细成荷塘浅笑的涟漪

                                                                                                     江南雨

                                                                                                     是阿婆河边捣的衣

                                                                                                     江南雨

                                                                                                     是阿妈屋前舂的米

                                                                                                     江南雨

                                                                                                     是水乡月上柳梢的洞箫

                                                                                                     江南雨

                                                                                                     是稻田夕阳晚照的竹笛

                                                                                                     江南雨中

                                                                                                     有一把圆圆的纸伞

                                                                                                     江南雨外

                                                                                                     有一个圆圆的思绪

                                                                                                     江南雨有情

                                                                                                     绵绵的使江南人不想离别

                                                                                                     江南雨有意

                                                                                                     密密的使乡外人不愿归