Many people like to watch 3D movies. But do you know the students in the US can watch 3D movies in class? They can learn a lot in 3D classes. In the US, some students can watch 3D movies in many classes, such as math, science and geometry（几何） classes. The 3D classes show a special world to the students. They can help students understand the knowledge（知识） better. Students can remember the knowledge easily.

    The students like 3D movies very much. They say, "It's not difficult to learn, because you can remember all the things in the movies, and it's fun to learn."