“老师，我想问您一个问题，今天我们观察的水以及平常喝的水都没有颜色，但昨天，我看了有线新闻报道，衡阳有一条“黑水”河，河中的水是黑色的，这是为什么呢？”这是我在教学《水》一课，让学生观察纯净水，了解水没有颜色时，一位学生提出的疑问。为了达到既解决学生问题 “Teacher, I would like to ask you a question. Today, the water we observe and the water we drink regularly have no color. But yesterday I read the cable news report that there was a” black water “river in Hengyang and the water in the river was black. Why is this? ”This is a question I raised when I was teaching“ Water ”to allow students to observe pure water and learn about water's lack of color. In order to achieve both solve student problems