对……补充：a supplement to…
Ladies and gentlemen,
Welcome to our English Corner. This Corner was set up three years ago. Every Sunday morning, students from different schools gathered around here. Many college students and some foreigners often join us, We practice spoken English by talking about everything we are interested in. We also exchange our experience in English study. We all have a good time here. Thousands of people have been here since it was set up.
We think that we have learned a lot by taking part in activities here. It is a real supplement to our English class and it is welcomed by students. Their parents and teachers. They all think it is helpful. If you want to know more about the corner, you may talk to the students here.