单项选择题

D
When we talk about intelligence, we do not mean the ability to get good scores in certain kinds of tests or even the ability to do well in school. By intelligence we mean a way of living and behaving, especially in a new or anxious situation. If we want to test intelligence, we need to find out how a person acts instead of how much he knows what to do.
For example, when in a new situation, an intelligent person thinks about the situation, not about himself or what might happen to him. He tries to find out all he can, and then he acts immediately and tries to do something about it. He probably isn’t sure how it will all work out, but at least he tries. And, if he can’t make things work out right, he doesn’t feel ashamed that he fails; he just tries to learn from his mistakes. An intelligent person, even if he is very young, has a special outlook(人生观) on life, special feeling about life, and knows how he fits into it.
If you look at children, you’ll see great difference between what we call "bright" children and "not bright" children. They are actually two different kinds of people, not just the same kind with different amounts of intelligence. For example, the bright child really wants to find out more about life--he tries to get in touch with everything around him. But the unintelligent child keeps more to himself and his own dream-world; he seems to have a wall between him and life in general. According to the passage the biggest difference between "bright" children and "not bright" children lies in ______.