I am a teacher in a college in a large city in China. One day, some students asked me to join them for dinner. They said they wanted to take me to a very special restaurant that had just opened. This new place served American food. The students were proud that their city had a restaurant that served fine American food. I was quite surprised when we got to the restaurant. My students had taken me to a very well-known fast food restaurant! What is the author's purpose?