摘要
Introduction I live near Kunyu River.Every day,I walk home under tree shadow along the winding marble railings from my school,the Capital Normal University High School.One day when I was in my 7th grade,I noticed there was sewage flowing out of a tube and sprea-
Introduction I live near Kunyu River. Every day, I walk home under tree shadow along the winding marble railings from my school, the Capital Normal University High School. One day when I was in my 7th grade, I noticed there was sewage flowing out of a tube and sprea- ding in the clear river, which shocked me and made me sad. After that I started to pay closer attention to the spread＇s pattern; I found out that when the sewage flew out of the tube, it spreads along with the flow forming a sewage zone parallel to the river bank. Because of this discovery, I came Up with the idea of studying the spread of sewage with existing knowledge to provide theoretical support to checking sewage pollution and protecting the beautiful Kunyu River.
