《回声》一文中的第四、五自然段写了青蛙妈妈投石击水,激起水波,以水波比声波,给小青蛙讲清了回声产生的道理。这部分内容是教材的重点,也是教学的难点。如何让学生既能明白产生回声的道理,又能受到语言文字方面的有效训练?我在教学中采用了如下的办法: 一、划句标词,读文想景。学生先自读第四自然段,划出表示河水变化的 Echo "in the article fourth, five paragraphs of the frog mother throw stone hit water, stir water waves to water waves than sound waves, to explain the small frog echoes the truth. This part of the textbook is the focus of teaching is also difficult. How to make students not only understand the echo of the truth, but also by the effective training of language? I used in teaching the following methods: First, the sentence tagging, read the text to King. Students first read the fourth paragraph of nature, drawn that changes in the river