单项选择题

Passage 2 　　Ask three people to look out the same window at a busy street corner and tell you what they see. Chances are you will receive three different answers. Each person sees the same scene, but each perceives something different about it. 　　Perceiving goes on in our minds. Of the three people who look out the window, one may say that he sees a policeman giving a motorist a ticket. Another may say that he sees a rush hour traffic jam at the intersection. The third may tell you that he sees a woman trying to cross the street with four children in a row. For perception is the mind’s interpretation of what his senses – in this case our eyes – tell us. 　　Many psychologists today are working to try to determine just how a person experiences or perceives the world around him. Using a scientific approach, these psychologists set up experiments in which they can control all of the factors. By measuring and charting the results of many experiments, they are trying to find out what makes different people perceive totally different things about the same scene. Which of the following statements is implied but not stated？